12009
4 and 5
6 and 3
8 and 1
6, 2 and 1
5, 3 and 1
5, 2 and 2
4, 3 and 2
and others
-8
Add them up. The factors of 9 are 1, 3 and 9. The sum of the factors is 13.
6 and 9
How about 3 and 6
268
9 is not a factor of 12000, If it were 12000 would be divisible by 9.
The factors of 9 are 1, 3, and 9. 1 + 3 + 9 = 13
7 and 2
9 and -3
5
9
You are 9.