21 has the factors 21,1,7,3. 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.
The factors of 21 are 1, 3, 7, and 21 which means that 21 is composite.
composite composite
composite
It is composite.
It's clearly not prime; no even number is prime. It is composite.
21 is composite.
21 is composite.
21 is composite
21 is a composite number
Composite
number 21 is prime
21 is composite. 19 and 23 are prime.
3 * 7 = 21 21 is not prime
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.
21 is a composite number.
21 is composite as 3 times 7 is 21 31 is prime