78
The factors of 21 that add up to 8 are 1 and 7.
15 and 4 are the factors of 120 that add up to 19.
The factors of -12 that add up to 1 are 4 and -3.
As a product of its prime factors: 2*3*13 = 78
23
The factors of 8 are 1, 2, 4, and 8. The factors that add up to 10 are 2 and 8.
-1005
167
Factors multiply. The same set of numbers won't add up to both 140 and 240, but 120 and 20 are factors of 240 that total 140.
factors of 30 that add to 17 are 2 and 15
37 & 41