21 is a composite number, as it can be divided by 7 and 3. The other three numbers are prime numbers and do not divide into anything besides themselves.
Chat with our AI personalities
The only composite factor of 21 is 21.
composite 3 and 119 7 and 51 17 and 21
21 is composite number because it has more than one number that goes into it
13
Who says it is? 21 is a composite number!