The Proper Divisors of any whole positive number are all its factors excluding the number itself.

 For example, the proper divisors of 24 are:    1, 2, 3, 4, 6, 8, and 12.

Interesting things happen if we add the proper divisors of any whole positive number.

For the number 8,   1 + 2 + 4 = 7.   7 < 8 so 8 is called a deficient number. 

For the number 12,   1 + 2 + 3 + 4 + 6  = 16.   16 > 12 so 12 is called an abundant number. 

For the number ,   1 + 2 + 3 = 6.   6 = 6  so 6 is called a perfect number.

Find out more about:

Deficient Numbers

Abundant Numbers

Perfect Numbers