➗ Prime Checker and Factorization
Enter a positive integer to see if it is prime, plus the full prime factorization when it is composite. Handy for homework and quick checks.
Input
Result
Summary
Private by design. This tool runs entirely in your browser — nothing you enter or add is uploaded to any server.
How it works
- Enter a positive integer up to 15 digits.
- Press Check. The page trial-divides by primes up to the square root.
- Read whether it is prime and the exponent form of its factors.
Examples
- 17 is prime, so the factorization is 17.
- 360 factors as 2^3 × 3^2 × 5.
- 1 is neither prime nor composite and is reported that way.
Frequently asked questions
What is the size limit?
Inputs longer than 15 digits are rejected so the page stays responsive. Use a computer-algebra tool for huge integers.
Are negatives accepted?
No. Primality is defined for integers greater than 1. Enter the absolute value.
Is the number uploaded?
No. Factorization runs in your browser.
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