Q: What are the prime factors of the number 666,555,561?

 A: 3, 7, 391861

Why are those the prime factors of the number 666,555,561?

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 666,555,561

666,555,561
Factor Arrows
3222,185,187
Factor Arrows
374,061,729
Factor Arrows
324,687,243
Factor Arrows
38,229,081
Factor Arrows
32,743,027
Factor Arrows
7391,861

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, 7, 391861

We can check our work by multiplying all of the prime factors together: 3 x 3 x 3 x 3 x 3 x 7 x 391,861 = 666,555,561

This can also be written as 35 x 71 x 391,8611 = 666,555,561

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


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