19 is a Prime number. Its only factors are 1 and 19.
21 is a composite number. Its factors are 1, 3, 7, and 21.
23 is a prime number. Its only factors are 1 and 23.
Wiki User
∙ 2012-01-10 23:06:16Wiki User
∙ 2014-02-21 14:06:3219 and 23 are prime numbers whereas 21 is a composite number
No, they are three numbers, not one. 21 is composite.
17, 19, 23, 29 and 31 are prime. 15, 21, 25 and 27 are composite..
19 and 23 are prime.
21, 55, 77, and 93 are composite numbers. 23 is a prime.
23 is prime. 21 is composite as it is 7x3. A prime number has only 2 factors which are 1 and itself. Composite numbers are every other positive integer except 1 and 0. 1 and 0 are neither prime, nor composite.
21 is composite. 19 and 23 are prime.
No, they are three numbers, not one. 21 is composite.
17, 19, 23, 29 and 31 are prime. 15, 21, 25 and 27 are composite..
21 is composite.
All the numbers are composite except the ones in bold: 18 19 20 21 22 23 24 25.
19 and 23 are prime.
15 is composite number 17, 19 and 23 are prime numbers.
1 and 19; 19 is prime. 1, 3, 7 and 21; 3 and 7 are prime. 1 and 23; 23 is prime.
21, 55, 77, and 93 are composite numbers. 23 is a prime.
23 is prime. 21 is composite as it is 7x3. A prime number has only 2 factors which are 1 and itself. Composite numbers are every other positive integer except 1 and 0. 1 and 0 are neither prime, nor composite.
They are all prime numbers except for 15 21 25 and 27 which are composite numbers
23 is prime, 66 is composite.