Prime numbers are like the Lego bricks of number theory, and if you’re a real math nerd you know you love number theory. But wading your way through a sea of composite numbers looking for those magic numbers at either end of the scale, either the noble primes themselves or those composite numbers with who have a really interesting family tree of primes that multiply out to their true quantitative majesty… So, what every number explorer needs is a prime factorization calculator, and I just built a really fun one here. It’s animated. And in color. And perfect for playing with numbers in the classroom, on your Smart Board or just whenever you’ve got a number that seems like it’s got an interesting prime pedigree… Prime factorizations are a great tool for figuring out greatest common divisors (or largest common denominators if that’s how you swing), or for finding the least common multiple. But naturally, this calculator will tell you quite promptly if a number is prime as well. Give it a try and see what you can discover about your own favorite number. It’s factor tree may actually surprise you… Prime Factorization Calculator