From 1 to 25 which number has the fewest factors ?

Answer 1

1

1 has only one factor which is itself.

2 3 5 7 11 13 17 19 and 23 are prime numbers.

They having only 2 factors ( 1 and itself).

Factors for other numbers:

factors of 4: 1 , 2 , 4

factors of 6: 1 , 2 , 3 , 6

factors of 8: 1 , 2 , 4 , 8

factors of 10: 1 , 2 , 5 , 10

factors of 12: 1 , 2, 3, 4, 6, 12

factors of 14: 1 , 2 , 7 , 14

factors of 16: 1 , 2 , 4 , 8 , 16

factors of 18: 1, 2, 3, 6, 9, 18

factors of 20: 1, 2, 4, 5, 10, 20

factors of 22: 1 , 2 , 11 , 22

factors of 24: 1, 2, 3 , 4 , 6 , 8 , 12 , 24

Answer 2

By the way 1 is also prime number.