Because 21 is a multiple of 1, 3, 7 and 21.
The numeral '21' is evenly divisible by 21, 7, 3, and 1.
1, 3, 7, 21
They are members of the infinite set of numbers of the form 21*k where k is an integer.
1, 13 1, 3, 7, 21
Because 21 is divisible by numbers other than 1 and 21. 21 is divisible by 1, 3, 7, 21
A prime number is any integer evenly divisible by only itself, and the number 1. Since 21 is divisible by 3 and 7, it is a composite number, not a prime number.No, 21 is not a prime number.21 is divisible by 1, 3, 7, & 21No. 21=3*7
No, it is composite. 21 is divisible by 1, 3, 7, and 21. =)
1, 3, 7, 21.
42 is divisible by: 1 2 3 6 7 14 21 and 42.
1, 3, 7, 9, 21, 63
1, 3, 7, 19, 21 and 399.
7,2,6,42,1, 21, 3,