Factors refer to whole numbers, not fractions.
4.0
3/5 9/15 447/745
yes any factor of nine can be divided by nine
no
70
If the sum of the digits of a given number equals nine or a multiple of nine, nine is a factor of that number.
No it isn't.
It is 3
Nine is the highest common factor of 81 and 9
3 is the only proper factor of 9.
The factors of 9 are 1, 3 and 9. The proper factor of 9 is 3.
1