And the principal reason why primes are important is that every number can be written as a product ofprime numbers, and that can be done in essentially only one way. To find this special factorization, wejust need to factorize the given number in some way and then continue factorizing any composite factors that appear until this can be done no more. For example, we could say that 120=2×60 and continue by breaking the composite factor of 60 down further to give: