Donaldson R F Prime Factorization Calculator
Enter a whole number to write it as a product of primes, with a step-by-step factor tree, its divisors and more.
Factor tree
Division ladder
What is prime factorization?
Every whole number greater than 1 is either prime or can be written in exactly one way as a product of prime numbers (the fundamental theorem of arithmetic). For example 360 = 2³ × 3² × 5. To find the factors, divide repeatedly by the smallest prime that goes in — the division ladder — or split the number into any two factors and keep splitting: the factor tree.
Prime factors give you the highest common factor and lowest common multiple of numbers (try the GCD & LCM calculator), simplify fractions and count divisors. To check whether one number is prime, use the prime number checker.