Q: What are the prime factors of the number 21,152,720?

 A: 2, 5, 41, 6449

Why are those the prime factors of the number 21,152,720?

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 21,152,720

21,152,720
Factor Arrows
210,576,360
Factor Arrows
25,288,180
Factor Arrows
22,644,090
Factor Arrows
21,322,045
Factor Arrows
5264,409
Factor Arrows
416,449

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, 5, 41, 6449

We can check our work by multiplying all of the prime factors together: 2 x 2 x 2 x 2 x 5 x 41 x 6,449 = 21,152,720

This can also be written as 24 x 51 x 411 x 6,4491 = 21,152,720

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


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