A Prime number is any integer evenly divisible by only itself, and the number 1. Since 21 is divisible by 3 and 7, it is a composite number, not a prime number.
No, 21 is not a prime number.
21 is divisible by 1, 3, 7, & 21
number 21 is prime
21 is a composite number, not a prime, having prime factors 3x7.
There is an infinite number of prime numbers that are greater than 21. The next prime number after 21 is 23.
11 is a prime number but 21 is not a prime number as it is divisible by 3.
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.
21 is composite number that is a multiple of 3. 31 is a prime number.
21 is a Composite Number. A prime number is a whole number that only has two factors which are itself and one. A composite number has factors in addition to one and itself. 21 is divisible by 3 and 7.
3 * 7 = 21 21 is not prime
Who says it is? 21 is a composite number!
21 is a composite number
No. The only factors of a prime number are 1 and itself. The only way that 21 could be a factor of a prime number is if it were a prime number, but it is not because 21 is also divisible by 3 and 7.