21 is a composite number
21 is composite.
The next composite number after 20 is 21.
It is composite. It is divisible by 3 and 7.
The first composite number greater than 21 is 22.
21 is composite.
The only composite factor of 21 is 21.
21 is composite.
21 is composite
21 is composite. It's the product of 7 and 3 .
21 is a composite number
21 is composite.
21 and 28 are composite.
33 and 21 are composite. So is 3321.
The next composite number after 20 is 21.
21 is composite. 19 and 23 are prime.
21 is composite as 3 times 7 is 21 31 is prime