Prime Factorization Calculator

Write any whole number as a product of primes, like 360 = 2³ × 3² × 5.

Whole numbers up to 10¹².
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Prime factorization
Prime factors
Number of divisors
All divisors
Prime?
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How to Find Prime Factors

Divide by the smallest prime that goes in evenly (2, then 3, 5, 7, …) and repeat with the result until you reach 1. Every whole number above 1 has exactly one prime factorization.

Number of divisors = (e₁ + 1)(e₂ + 1)… for n = p₁^e₁ × p₂^e₂ × …

Worked Example

Tips

You only need to test divisors up to the square root of what’s left; if none divide it, what’s left is prime. This page uses exact whole-number math up to 10¹².