Q: What are the prime factors of the number 21,756,728?

 A: 2, 7, 29, 13397

Why are those the prime factors of the number 21,756,728?

Prime factors are the prime numbers that can be multipled together to equal the original number. You find the factors by dividing by prime numbers. It is best shown by creating a Factor Tree.

Factor Tree for the number 21,756,728

21,756,728
Factor Arrows
210,878,364
Factor Arrows
25,439,182
Factor Arrows
22,719,591
Factor Arrows
7388,513
Factor Arrows
2913,397

The numbers in bold above are the prime factors. If there are multiples, you only count them one time. This leads us to our prime factors of:

2, 7, 29, 13397

We can check our work by multiplying all of the prime factors together: 2 x 2 x 2 x 7 x 29 x 13,397 = 21,756,728

This can also be written as 23 x 71 x 291 x 13,3971 = 21,756,728

If you would like to know more, or need additional explanation, please review our prime factorization explanation.


More Examples

Here are some more numbers to try:

Try the factor calculator

Explore more about the number 21,756,728:


Ask a Question