Sum of divisors: 980.
1, 2, 4, 139, 278, 556 2 and 139 are prime.
556 + 323 = 879 whose digits sum to 24.
2 x 2 x 139
The sets are 277, 279 and 136, 138, 140, 142.
The sum of the factors of 10,752 is 32,736.
556
556 * 556 = 309,136
154 is the sum of the proper factors of 256.
The sum of the positive factors of 504 is: 1,560
The sum of the factors of any negative number is zero.
The sum is 121.