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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
No. 21=3*7
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Continue Learning about Basic Math
Is 21 a prime number of composite?
21 is a composite number
Which of these numbers is not a prime number A 21 B 31 C 41?
21 is not a prime.
Which is prime 21 33 47 78?
47 is a prime number.
Why is 21 not a prime number?
21 isn't a prime number because it has more factors than just itself and 1 3x7=21 21x1=21
What is the prime number out of 21 23 and 25?
21 = 3 x 7, so it is not a prime number. 23 = 1 x 23, it does not have any other factors, so it is a prime number. 25 = 5 x 5, so it is not a prime number.
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