Factor a number into primes
Every integer splits into one unique set of prime factors. Get that factorization, the divisor count, and the divisor list for any number up to 10¹⁵.
Tools used in this guide
The job
You need a number's prime factors — to simplify a fraction, find a least common multiple by hand, check whether a number is prime, or answer a homework problem. Enter the integer and read the factorization with exponents.
How to do it
Type a whole number from 2 to 10¹⁵ and run it. The result shows the prime factors (360 = 2³ × 3² × 5), whether the number is prime, how many divisors it has, and the divisor list itself — capped at 200 entries for readability.
Worked example
Factoring 360 gives 2³ × 3² × 5 and 24 divisors. To simplify 360/525 by hand, factor 525 the same way — 3 × 5² × 7 — then cancel the shared 3 and 5 to get 24/35.
Limits
Trial division means a large prime near the 10¹⁵ cap takes a moment to confirm. Negative numbers are rejected — factor the magnitude and apply the sign yourself. No decimals: multiply by a power of ten and factor the integer instead.