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1 is not composite or prime.

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1 is not either.

Q: Which number is not a prime or a composite number 21 15 8 and 1?

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number 21 is prime

21 is a composite number, not a prime, having prime factors 3x7.

Who says it is? 21 is a composite 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.

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31 and 61 are prime, the rest composite.

21 is a composite number

number 21 is prime

27 is composite. 27 = 3 * 3 * 3 = 3315 is composite. 15 = 3 * 521 is composite. 21 = 3 * 723 is a prime number. It is only evenly divisible by itself and one.

21 is a composite number, not a prime, having prime factors 3x7.

Not necessarily. For example 15 and 16 are composite numbers. They add to 31, which is a prime number. Similarly, the composite numbers 20 and 21 add up to 41, which is a prime number.

Who says it is? 21 is a composite number!

21 is a composite number.

21 is a composite number.

3 * 7 = 21 21 is not prime

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.