The sum of the proper divisors of 18 is 21. What is the sum of the proper divisors of 198?
(1, 2, 3, 6, 9, 11, 18, 22, 33, 66, 99, 198) >>Total = 12 Divisors
[1+2+3+6+9+11+18+22+33+66+99] = 270 - Sum of the proper divisors of 198.
