A Prime number has only 2 factors which are 1 and itself. Composite numbers are everything else except 1 and 0. 1 and 0 are neither prime, nor composite. 21 is composite.
21 is a composite number
number 21 is prime
Composite
Composite.
21 is a Composite Number. A prime number is a whole number that only has two factors which are itself and one. A composite number has factors in addition to one and itself. 21 is divisible by 3 and 7.
Composite, 21=3*7
21 is a composite number, not a prime, having prime factors 3x7.
Who says it is? 21 is a composite number!
21 is a composite number.
21 is a composite number.
3 * 7 = 21 21 is not prime
21 is composite number that is a multiple of 3. 31 is a prime number.