# Is 4 a Factor of 21?

In this article we are going to check whether 4 is a factor of 21 and explain the two easiest methods to calculate this for yourself.

What we can do is list out all of the factors of 21 and then check the resulting list to see if 4 is one of those numbers. Here are all the factors of 21:

• 1
• 3
• 7
• 21

We can also list the factors of 21 into a comma separated list as well:

1, 3, 7, and 21

We are checking to see if the number 4 is in this list and we can clearly see that it is not in the list of factors for 21.

This means, 4 is not a factor of 21.

We can also check whether 4 is a factor of 21 by simplying dividing 21 by 4 to see if the quotient (the resulting answer) is a whole or a fractional number.

If the result is a whole number, then we know that 4 is a factor of 21.

If the result is a fractional number, then we know that 4 is not a factor of 21.

21 divided by 4 is 5.25 which is a fractional number. This confirms our answer from the factor list method above that 4 is not a factor of 21.

Hopefully this has not only answered the question "is 4 a factor of 21?", but also explained the methods for working this out for yourself.

Challenge yourself to try and calculate whether one number is a factor of another using both of the methods above to practice your new understanding of factors.

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• "Is 4 a Factor of 21?". DivisibleBot.com. Accessed on October 22, 2021. https://divisiblebot.com/factor-checker/is-4-a-factor-of-21/.

• "Is 4 a Factor of 21?". DivisibleBot.com, https://divisiblebot.com/factor-checker/is-4-a-factor-of-21/. Accessed 22 October, 2021.