Q: What are the prime factors of the number 21,385,428?

 A: 2, 3, 139, 12821

Why are those the prime factors of the number 21,385,428?

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 21,385,428

21,385,428
Factor Arrows
210,692,714
Factor Arrows
25,346,357
Factor Arrows
31,782,119
Factor Arrows
13912,821

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, 3, 139, 12821

We can check our work by multiplying all of the prime factors together: 2 x 2 x 3 x 139 x 12,821 = 21,385,428

This can also be written as 22 x 31 x 1391 x 12,8211 = 21,385,428

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 21,385,428:


Ask a Question