Q: What is the sum of all factors of the number 1,287 excluding 1,287?
A: 897
The factors of the number 1,287 are: 1, 3, 9, 11, 13, 33, 39, 99, 117, 143, 429, 1287.
If you add them up, you will get the total of 2,184. Now subtract 1,287 to get 897