Prime Factorization Calculator

Enter a whole number from 2 to 1,000,000,000,000 to see its prime factors.

Result

Enter values and press Calculate to see the result.

Formula

n=p1e1×p2e2×⋯n = p_1^{e_1} \times p_2^{e_2} \times \cdots

Every whole number above 1 is a product of primes in exactly one way (the fundamental theorem of arithmetic).

d(n)=(e1+1)(e2+1)⋯d(n) = (e_1 + 1)(e_2 + 1)\cdots

The number of divisors comes straight from the exponents.

How to use this calculator

  1. Enter the number without separators, e.g. 360.
  2. Press Calculate. Each step divides out one prime.

Worked example

Prime factors of 360

360 ÷ 2³ = 45, 45 ÷ 3² = 5, and 5 is prime.

So 360 = 2³ × 3² × 5, with (3+1)(2+1)(1+1) = 24 divisors.

Frequently asked questions

Is 1 a prime number?

No. A prime has exactly two divisors, 1 and itself; 1 has only one.

Why is there an upper limit?

Factorising very large numbers takes a long time. Up to one trillion, the result is guaranteed and instant.

Learn more