**Factors of 1**

The number 1 has only one factor which is 1. As 1 is not a prime number, we can say that 1 has no prime factors. For more details, visit Factors of 1.

Note that 1 is neither a prime number nor a composite number.

**Factors of 2**

The factors of 2 are 1 and 2. The only prime factor of 2 is 2. If you want to know more, click on Factors of 2.

The number 2 is a prime number.

**Factors of 3**

The factors of 3 are 1 and 3. Note that the only prime factor of 3 is 3.

As 3 has only two factors 1 and 3 itself, we say that 3 is a prime number.

**Factors of 4**

The factors of 4 are 1, 2, and 4. The only prime factor of 4 is 2.

The number 4 is not a prime number, it is a composite number.

**Factors of 5**

The factors of 5 are 1 and 5. Note that the only prime factor of 5 is 5.

As 5 has only two factors 1 and 5, the number 5 is a prime number.

**Factors of 6**

The factors of 6 are given as follows: 1, 2, 3, and 6. Here 2 and 3 are prime numbers, so the prime factors of 6 are 2 and 3. For more details, click on Factors of 6.

As 6 has factors other than 1 and 6, we conclude that 6 is a composite number

Conclusion: 6 is not a prime number.

**Factors of 7**

The factors of 7 are 1 and 7. Note that 7 is the only prime factor of 7.

We see that 1 and 7 are the only factors of 7. Thus 7 is a prime number.

**Factors of 8**

The factors of 8 are 1, 2, 4, and 8. Here 2 is the only prime number. Thus 2 is the only prime factor of 8. For more details, visit Factors of 8.

Note that 2 and 4 are the proper divisors of 8. So 8 is a composite number.

Conclusion: 8 is not a prime number.

**Factors of 9**

The factors of 9 are 1, 3, and 9. Here only 3 is the prime number. So the only prime factor of 9 is 3.

As 9 has proper divisor 3, the number 9 is not a prime number. It is a composite number.

**Factors of 10**

The factors of 10 are given as follows: 1, 2, 5, and 10. Here 2 and 5 are prime numbers. So the prime factors of 10 are 2 and 5. For more details, visit Factors of 10.

As 10 has factors other than 1 and 10, we conclude that 10 is a composite number.

Conclusion: 10 is not a prime number.

**Factors of 11**

The factors of 11 are 1 and 11. Note that 11 is the only prime factor of 11.

We observe that 1 and 11 are the only factors of 11. Thus 11 is a prime number.

**Factors of 12**

The factors of 12: 1, 2, 3, 4, 6, and 12.

**Factors of 13**

The factors of 13 are 1 and 13. Note that 13 is the only prime factor of 13.

As 1 and 13 are the only factors of 13, we conclude 13 is a prime number.

**Factors of 14**

The factors of 14 are given as follows: 1, 2, 7, and 14. Here 2 and 7 are prime numbers. So the prime factors of 10 are 2 and 7.

As 14 has factors other than 1 and 14, we conclude that 14 is a composite number

Conclusion: 14 is not a prime number.

**Factors of 15**

Factors of 15: 1, 3, 5, and 15.

Prime factors of 15: 3 and 5.

For more details, click on factors of 15. As 3 and 5 are proper factors of 15, we have that 15 is a composite number. Conclusion: 15 is not a prime number

**Factors of 16**

Factors of 16: 1, 2, 4, 8, and 16.

See that 2 is the only prime factor of 16.

For more details, click on factors of 16. As 2 is a proper factor of 16, the number 16 is a composite number. It is not a prime number.

**Factors of 17**

The factors of 17 are 1 and 17. Note that 17 is the only prime factor of 17.

As 1 and 17 are the only factors of 17, we conclude 17 is a prime number.

**Factors of 18**

The factors of 18 are 1, 2, 3, 6, 9, and 18.

**Factors of 19**

The factors of 19 are 1 and 19. The only prime factor of 19 is 19.

As 1 and 19 are the only factors of 19, we conclude 19 is a prime number.

**Factors of 20**

The factors of 20 are 1, 2, 4, 5, 10, and 20.

**Factors of 21**

The factors of 21 are 1, 3, 7, and 21.

**Factors of 22**

The factors of 22 are 1, 2, 11, and 22.

**Factors of 23**

The factors of 23 are 1 and 23. The only prime factor of 23 is 23.

As 1 and 23 are the only factors of 23, we deduce that 23 is a prime number.

**Factors of 24**

Factors of 24: 1, 2, 3, 4, 6, 8, 12, and 24.

Prime factors of 24: 2 and 3.

**Factors of 25**

The factors of 25 are 1, 5, and 25.

**Factors of 26**

The factors of 26 are 1, 2, 13, and 26.

**Factors of 27**

The factors of 27 are 1, 3, 9, and 27.

**Factors of 28**

The factors of 28 are 1, 2, 4, 7, 14, and 28.

**Factors of 29**

The factors of 29 are 1 and 29. The only prime factor of 29 is 29.

Note that 1 and 29 are the only factors of 29. Hence 29 is a prime number.

**Factors of 30**

The factors of 30 are 1, 2, 3, 5, 6, 10, 15, and 30.

**Factors of 31**

The factors of 31 are 1 and 31.

**Factors of 32**

The factors of 32 are 1, 2, 4, 8, 16, and 32.

**Factors of 33**

The factors of 33 are 1, 3, 11, and 33.

**Factors of 34**

The factors of 34 are 1, 2, 17, and 34.

**Factors of 35**

The factors of 35 are 1, 5, 7, and 35.

**Factors of 36**

The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, and 36.

**Factors of 37**

The factors of 37 are 1 and 37.

**Factors of 38**

Factors of 38: 1, 2, 19, and 38.

**Factors of 39**

Factors of 39: 1, 3, 13, and 39.

**Factors of 40**

The factors of 40 are 1, 2, 4, 5, 8, 10, 20, and 40.

**Factors of 41**

The factors of 41 are 1 and 41.

**Factors of 42**

The factors of 42 are 1, 2, 3, 6, 7, 14, 21, and 42.

**Factors of 43**

The factors of 43 are 1 and 43.

**Factors of 44**

The factors of 44 are 1, 2, 4, 11, 22, and 44.

**Factors of 45**

The factors of 45 are 1, 3, 5, 9, 15, and 45.

**Factors of 46**

The factors of 46 are 1, 2, 23, and 46.

**Factors of 47**

The factors of 47 are 1 and 47.

**Factors of 48**

The factors of 48 are 1, 2, 3, 4, 6, 8, 12, 16, 24, and 48.

**Factors of 49**

The factors of 49 are 1, 7, and 49.

**Factors of 50**

The factors of 50 are 1, 2, 5, 10, 25, and 50.

**Factors of 51**

The factors of 51 are 1, 3, 17, and 51. As 3 and 17 here are prime numbers, the prime factors of 51 are 3 and 17.

As 51 has proper factors 3 and 17, the number 51 is a composite number. So we have:

51 is not a prime number.

**Factors of 52**

The factors of 52 are 1, 2, 4, 13, 26, and 52.

**Factors of 53**

The factors of 53 are 1 and 53.

**Factors of 54**

The factors of 54 are 1, 2, 3, 6, 9, 18, 27, and 54. We see that among these numbers only 2 and 3 are prime numbers. So the prime factors of 54 are 2 and 3.

As 54 has factors other than 1 and the number 54 itself, we conclude that 54 is a composite number.

∴ 54 is not a prime number.

**Factors of 55**

The factors of 55 are 1, 5, 11, and 55.

**Factors of 56**

The factors of 56 are 1, 2, 4, 7, 8, 14, 28, and 56.

**Factors of 57**

The factors of 57 are 1, 3, 19, and 57. As 3 and 19 here are prime numbers, the prime factors of 57 are 3 and 19.

As 57 has proper factors 3 and 19, the number 57 is a composite number. So we have:

57 is not a prime number.

**Factors of 58**

The factors of 58 are 1, 2, 29, and 58.

**Factors of 59**

The factors of 59 are 1 and 59.

**Factors of 60**

The factors of 60 are 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60.

**Factors of 61**

The factors of 61 are 1 and 61.

**Factors of 62**

The factors of 62 are 1, 2, 31, and 62.

**Factors of 63**

The factors of 63 are 1, 3, 7, 9, 21, and 63.

**Factors of 64**

The factors of 64 are 1, 2, 4, 8, 16, 32, and 64.

**Factors of 65**

The factors of 65 are 1, 5, 13, and 65.

**Factors of 66**

The factors of 66 are 1, 2, 3, 6, 11, 22, 33, and 66.

**Factors of 67**

The factors of 67 are 1 and 67.

**Factors of 68**

The factors of 68 are 1, 2, 4, 17, 34, and 68.

**Factors of 69**

The factors of 69 are 1, 3, 23, and 69.

**Factors of 70**

The factors of 70 are 1, 2, 5, 7, 10, 14, 35, and 70.

**Factors of 71**

The factors of 71 are 1 and 71.

**Factors of 72**

The factors of 72 are 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, and 72. Here 2 and 3 are prime numbers. So we can say that the prime factors of 72 are 2 and 3.

As 2 is a proper factor of 72, the number 72 is a composite number. So we have:

72 is not a prime number

**Factors of 73**

The factors of 73 are 1 and 73.

**Factors of 74**

The factors of 74 are 1, 2, 37, and 74.

**Factors of 75**

The factors of 75 are 1, 3, 5, 15, 25, 75.

**Factors of 76**

The factors of 76 are 1, 2, 4, 19, 38, and 76.

**Factors of 77**

The factors of 77 are 1, 7, 11, and 77.

**Factors of 78**

The factors of 78 are 1, 2, 3, 6, 13, 26, 39, and 78.

**Factors of 79**

The factors of 79 are 1 and 79.

**Factors of 80**

The factors of 80 are 1, 2, 4, 5, 8, 10, 16, 20, 40, and 80.

**Factors of 81**

The factors of 81 are 1, 3, 9, 27, and 81.

**Factors of 82**

The factors of 82 are 1, 2, 41, and 82.

**Factors of 83**

The factors of 83 are 1 and 83.

**Factors of 84**

The factors of 84 are 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, and 84.

**Factors of 85**

The factors of 85 are 1, 5, 17, and 85.

**Factors of 86**

The factors of 86 are 1, 2, 43, and 86.

**Factors of 87**

The factors of 87 are 1, 3, 29, and 87.

**Factors of 88**

The factors of 88 are 1, 2, 4, 8, 11, 22, 44, and 88.

**Factors of 89**

The factors of 89 are 1 and 89.

**Factors of 90**

The factors of 90 are 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, and 90.

**Factors of 91**

The factors of 91 are 1, 7, 13, and 91.

**Factors of 92**

The factors of 92 are 1, 2, 4, 23, 46, and 92.

**Factors of 93**

The factors of 93 are 1, 3, 31, and 93.

**Factors of 94**

The factors of 94 are 1, 2, 47, and 94.

**Factors of 95**

The factors of 95 are 1, 5, 19, and 95.

**Factors of 96**

The factors of 96 are 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, and 96.

**Factors of 97**

The factors of 97 are 1 and 97.

**Factors of 98**

The factors of 98 are 1, 2, 7, 14, 49, and 98.

**Factors of 99**

The factors of 99 are 1, 3, 9, 11, 33, and 99.

**Factors of 100**

The factors of 100 are 1, 2, 4, 5, 10, 20, 25, 50, and 100.

**Factors of 101**

The factors of 101 are 1 and 101.

**Factors of 102**

The factors of 102 are 1, 2, 3, 6, 17, 34, 51, and 102.

**Factors of 103**

The factors of 103 are 1 and 103.

**Factors of 104**

The factors of 104 are 1, 2, 4, 8, 13, 26, 52, and 104.

**Factors of 105**

The factors of 105 are 1, 3, 5, 7, 15, 21, 35, and 105.

**Factors of 106**

The factors of 106 are 1, 2, 53, and 106.

**Factors of 107**

The factors of 107 are 1 and 107.

**Factors of 108**

The factors of 108 are 1, 2, 3, 4, 6, 9, 12, 18, 27, 36, 54, and 108. The prime factors of 108 are 2 and 3.

**Factors of 109**

The factors of 109 are 1 and 109.

**Factors of 110**

The factors of 11o are 1, 2, 5, 10, 11, 22, 55, and 110.

**Factors of 111**

The factors of 111 are 1, 3, 37, and 111.

**Factors of 112**

The factors of 112 are 1, 2, 4, 7, 8, 14, 16, 28, 56, and 112.

**Factors of 113**

The factors of 113 are 1 and 113.

**Factors of 114**

The factors of 114 are 1, 2, 3, 6, 19, 38, 57, and 114.

**Factors of 115**

The factors of 115 are 1, 5, 23, and 115.

**Factors of 116**

The factors of 116 are 1, 2, 4, 29, 58, and 116.

**Factors of 117**

The factors of 117 are 1, 3, 9, 13, 39, and 117.

**Factors of 118**

The factors of 118 are 1, 2, 59, and 118.

**Factors of 119**

The factors of 119 are 1, 7, 17, and 119.

**Factors of 120**

The factors of 120 are 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, and 120.

**Factors of 121**

The factors of 121 are 1, 11, and 121.

**Factors of 122**

The factors of 122 are 1, 2, 61, and 122.

**Factors of 123**

The factors of 123 are 1, 3, 41, and 123.

**Factors of 124**

The factors of 124 are 1, 2, 4, 31, 62, and 124.

**Factors of 125**

The factors of 125 are 1, 5, 25, and 125.

**Factors of 126**

The factors of 126 are 1, 2, 3, 6, 7, 9, 14, 18, 21, 42, 63, and 126.

**Factors of 127**

The factors of 127 are 1 and 127.

**Factors of 128**

The factors of 128 are 1, 2, 4, 8, 16, 32, 64, and 128.

**Factors of 129**

The factors of 129 are 1, 3, 43, and 129.

**Factors of 130**

The factors of 130 are 1, 2, 5, 10, 13, 26, 65, and 130.

**Factors of 131**

The factors of 131 are 1 and 131.

**Factors of 132**

The factors of 132 are 1, 2, 3, 4, 6, 11, 12, 22, 33, 44, 66, and 132.

**Factors of 133**

The factors of 133 are 1, 7, 19, and 133.

**Factors of 134**

The factors of 134 are 1, 2, 67, and 134.

**Factors of 135**

The factors of 135 are 1, 3, 5, 9, 15, 27, 45, and 135.

**Factors of 136**

The factors of 136 are 1, 2, 4, 8, 17, 34, 68, and 136.

**Factors of 137**

The factors of 137 are 1 and 137.

**Factors of 138**

The factors of 138 are 1, 2, 3, 6, 23, 46, 69, and 138.

**Factors of 139**

The factors of 139 are 1 and 139.

**Factors of 140**

The factors of 140 are 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, and 140.

**Factors of 141**

The factors of 141 are 1, 3, 47, and 141.

**Factors of 142**

The factors of 142 are 1, 2, 71, and 142.

**Factors of 143**

The factors of 143 are 1, 11, 13, and 143.

**Factors of 144**

The factors of 144 are 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 36, 48, 72, and 144.

**Factors of 145**

The factors of 145 are 1, 5, 29, and 145.

**Factors of 146**

The factors of 146 are 1, 2, 73, and 146.

**Factors of 147**

The factors of 147 are 1, 3, 7, 21, 49, and 147.

**Factors of 148**

The factors of 148 are 1, 2, 4, 37, 74, and 148.

**Factors of 149**

The factors of 149 are 1 and 149.

**Factors of 150**

The factors of 150 are 1, 2, 3, 5, 6, 10, 15, 25, 30, 50, 75, and 150.

This article is written by Dr. T. Mandal, Ph.D in Mathematics. On Mathstoon.com you will find Maths from very basic level to advanced level. Thanks for visiting.