Q: What are the prime factors of the number 21,351,681?

 A: 3, 13, 751

Why are those the prime factors of the number 21,351,681?

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 21,351,681

21,351,681
Factor Arrows
37,117,227
Factor Arrows
32,372,409
Factor Arrows
3790,803
Factor Arrows
3263,601
Factor Arrows
387,867
Factor Arrows
329,289
Factor Arrows
39,763
Factor Arrows
13751

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:

3, 13, 751

We can check our work by multiplying all of the prime factors together: 3 x 3 x 3 x 3 x 3 x 3 x 3 x 13 x 751 = 21,351,681

This can also be written as 37 x 131 x 7511 = 21,351,681

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


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