Prime Factorization

The Prime Factorization tool breaks a whole number down into the prime numbers that multiply together to make it, the unique fingerprint guaranteed by the fundamental theorem of arithmetic.

Type any integer of two or greater and it returns the factorization in clear exponent form, such as 360 = 2^3 × 3^2 × 5, alongside the fully expanded list of factors with repeats so you can see exactly how the number is built.

When the number you enter is itself prime, the tool says so directly instead of just echoing it back.

Under the hood it uses trial division, peeling off factors of two and then testing odd divisors up to the square root of what remains, which keeps results exact with no floating-point rounding and is fast across a wide range of inputs.

It is handy for homework and number-theory practice, for simplifying fractions, for finding greatest common divisors and least common multiples by hand, and for understanding the structure of a number at a glance.

Very large values are capped at the safe integer limit so every answer it gives is mathematically exact rather than approximate.

Everything runs locally in your browser, so nothing you enter is uploaded, logged or stored, and the tool keeps working offline once the page has loaded.