Q: What is the sum of all factors of the number 81,991 excluding 81,991?
A: 26,873
The factors of the number 81,991 are: 1, 7, 13, 17, 53, 91, 119, 221, 371, 689, 901, 1547, 4823, 6307, 11713, 81991.
If you add them up, you will get the total of 82,017. Now subtract 81,991 to get 26,873