Well, 18 and 3 (both factors of 36) add up to 21. As well, the factors 12 and 9 add up to 21.
2 AND 21 there is only one factor that adds up to 23 and if you multiple 21 times 2 =42
21
The factors of 21 are 1, 3, 7 and 21. No two of them add up to 21.
364
25
Factors are numbers you can multiply together to get another number. Therefore, all the factors of 21 are as follows: 1,3,7,21.
-25
41
The factors of twenty-one are the numbers that can be multiplied together to yield twenty-one. These factors are 1, 3, 7, and 21. Specifically, 1 × 21 and 3 × 7 both equal 21.
Factors are numbers you can multiply together to get another number. 21: (1, 21) (3, 7)
-21 and -1
48, because it adds another 2 to the prime factorization.