4 (its factor is: 1, 2,4)

9 (its factor is: 1, 3,9)

There are exactly four factors:

6 (its factor is: 1, 2, 3, 6)

8 (its factor is: 1, 2, 4, 8)

10 (its factor is: 1, 2,5, 10)

14 (its factor is: 1, 2,7, 14)

15 (its factor is: 1, 3,5, 15)

There are exactly five factors:

16 (its factor is: 1, 2,4,8, 16)

There are exactly six factors:

12 (its factors are: 1, 2, 3, 4, 6, 12)

18 (the factors are: 1, 2, 3, 6, 9, 18.

I hope I am satisfied! !