No 21 is not a Prime number because it has more than two factors therefore it is a composite number
21 is the product of two prime numbers, three and seven. A prime number is defined as a number divisible only by one or itself. So ... NO ... 21 is not a prime number.
23 is a prime number.
Only 23 is a prime number.
19 and 23 are prime.
21 x 2 does not equal 40. 21 is not a prime number.
The prime factorization of 21 is: 3 x 7
47 is a prime number 21 & 87 divisible by 3, and 4 is divisible by 2
23
Do you mean, "What is the prime factorization of 21?"
The prime factorization for 21 is 3x7.
21 is not prime.
It can be. 21 is relatively prime with 32.