**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.