4, 21
No, they are three numbers, not one. 21 is composite.
19 is prime number. 10, 21 and 62 are composite numbers.
composite numbers between 11 and 21:12 14 15 16 18
19. It is prime.
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.
21 is composite. 19 and 23 are prime.
Between 11 and 21: 12, 14, 15, 16, 18 and 20.
21 is composite.
Prime numbers: 11, 13, 17, 19, 23, 29 Composite numbers: 10, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 27, 28, 30
All the numbers are composite except the ones in bold: 18 19 20 21 22 23 24 25.
3, 7, and 19 have only two factors, 1 and itself. They are prime numbers. 21 has more than 2 factors: 1, 3, 7, and 21. It is a composite number.
They are all prime numbers except for 15 21 25 and 27 which are composite numbers