# How do you write a prime factorization?

All composite numbers can be expressed as unique products of prime numbers. This is accomplished by dividing the original number and its factors by prime numbers until all the factors are prime. A factor tree can help you visualize this.

Example: 210

210 Divide by two.

105,2 Divide by three.

35,3,2 Divide by five.

7,5,3,2 Stop. All the factors are prime.

2 x 3 x 5 x 7 = 210

That's the prime factorization of 210.

### What are some methods for determining prime factorization?

There are factor trees and ladders and rainbows and fireworks and they're all pretty much the same thing: ways to notate the process of finding the prime factorization of a given number. They differ in where they write the number and where the factors end up. In a factor tree, write the original number at the top and the bottommost branch will be the prime factorization. In a factor rainbow, write the original number at…