15 and 2
A perfect number, like 6.
41
2 + 3 + 5 = 10
3, 12, 30
The least common factor of any set of integers is 1.
a proper factor is a factor.
It is 15*(1 + 2)
154 is the sum of the proper factors of 256.
(5 x 6) + (9 x 6) = 14 x 6 = 84
1, 2, 3, 5, 6, 10 and 15. Some people do not consider 1 to be a proper factor.
No. Prime numbers don't have proper factors.