The proper divisors of 12 are 1, 2, 3, 4 and 6. A proper divisor of an integer N is a positive divisor of N that is less than N. What is the sum of the proper divisors of 284?
284 ==(1, 2, 4, 71, 142, 284)>>Total = 6 divisors
ADD them up on your calculator except 284 itself.