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Prime Factorizer

Break any integer into its prime factors.

Prime factorization
23×32×5
Expanded: 2 × 2 × 2 × 3 × 3 × 5

About

Type a positive integer. The tool finds its prime factorization (the unique product of primes that equals it). Tells you when a number is prime. Works for inputs up to 10^15 with simple trial division.

How to use

  1. Type a positive integer.
  2. Read the prime factorization (or 'is prime').

FAQ

Why does this matter?+

Every integer has a unique prime factorization (the fundamental theorem of arithmetic). It's how RSA encryption works (it's hard to factor huge numbers), how we reduce fractions, and how we find divisibility rules.

Why a 10^15 limit?+

Trial division gets slow past that. Real factorization tools use clever algorithms to go further. For everyday use, 10^15 covers everything.