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Prime Factorization Calculator

Break a number into its prime factors, with each division shown.

About the Prime Factorization Calculator

Every whole number above 1 is either prime or a unique product of primes (the fundamental theorem of arithmetic). Divide by the smallest prime that fits, repeat with the result, and stop at 1.

The formula

n = p₁^a × p₂^b × p₃^c × …

p
prime numbers in increasing order
a, b, c
how many times each divides n

Worked example

8,400

  1. 8,400 = 2⁴ × 3 × 5² × 7

Questions people ask

Is 1 a prime number?

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

What's a factor tree?

A diagram of the same process: split the number into two factors, and keep splitting until every branch ends in a prime.