You just divide it by 21 and if there is no remainder then it went in evenly.
3, 6, 9, 12, 15, 18, 21
1, 3, 7, 21.
67 is a prime number, but 21 isn't. A prime number can only be evenly divided by '1' and itself. 21 can be evenly divided by 1, 3, 7, and 21.
21
The number 7
Only the number one.
0.21 If you want to find what goes into 21 100 times evenly all you have to do is divide 21 by 100.
Factors are those numbers which can be evenly divided into a number. The factors of 21 would be 1, 3, 7, 21 The factors of 28 would be 1, 2, 4, 7, 14, 28 The factors of 15 would be 1, 3, 5, 15
3
1 and 7
3