Q: What are the prime factors of the number 21,540,990?

 A: 2, 3, 5, 41, 83, 211

Why are those the prime factors of the number 21,540,990?

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 21,540,990

21,540,990
Factor Arrows
210,770,495
Factor Arrows
33,590,165
Factor Arrows
5718,033
Factor Arrows
4117,513
Factor Arrows
83211

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, 5, 41, 83, 211

We can check our work by multiplying all of the prime factors together: 2 x 3 x 5 x 41 x 83 x 211 = 21,540,990

This can also be written as 21 x 31 x 51 x 411 x 831 x 2111 = 21,540,990

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


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