Prime Factorization Calculator — Factors, Divisors & Prime Test
Break any positive integer into its prime factors in exponent form (e.g. 360 = 2³ × 3² × 5), count its divisors, list them, and test whether the number is prime.
🔒 Runs entirely in your browser. Your input and output are never sent to a server or stored — fully private.
Factors by trial division — a large prime can take a moment. Click the result to copy.
About this tool
This prime factorization calculator breaks a whole number down into the prime numbers that multiply together to make it, and writes the result in neat exponent form. It also tells you straight away whether the number itself is prime. Enter any integer and watch its factors resolve into primes such as 2, 3, 5 and 7. The factoring runs entirely in your browser, however large the number you try.
Frequently asked questions
What does prime factorization in exponent form mean?
It expresses a number as a product of primes, grouping repeated factors as powers. For example 360 factors into 2 × 2 × 2 × 3 × 3 × 5, which is written 2³ × 3² × 5 in exponent form. Every whole number above 1 has exactly one such factorization, which is why it is the foundation for finding divisors, common factors and multiples.
How does it check whether a number is prime?
A prime number has no divisors other than 1 and itself. The tool tries to factor your number, and if the only factors are 1 and the number, it reports that the number is prime. In practice it tests divisibility by primes up to the square root of the number, which is enough to settle the question quickly for everyday inputs.
Is the number I enter sent anywhere?
No. The factoring happens entirely in your browser, so the number you enter is never sent to or stored on any server. Very large numbers take more computation to factor, but the work still runs on your own device, with nothing uploaded and nothing to install. You can refresh or close the page and no trace of your input is kept.