Prime Checker & Factorizer
Check whether a number is prime and get its full prime factorization (works up to a quadrillion). Runs in your browser.
Runs in your browser — your file never leaves your deviceFrequently asked questions
Is Prime Checker & Factorizer free to use?
Yes — Prime Checker & Factorizer is completely free with no limits, no watermarks and no sign-up. It runs in your browser, so there is nothing to pay for.
Are my files uploaded or stored anywhere?
No. This tool does all its work locally in your browser using your own device's power. Your files never leave your device and we never see them.
Do I need to install anything or create an account?
No installation and no account needed. Prime Checker & Factorizer works on any modern browser — Windows, Mac, Linux, Android and iPhone.
How do I use Prime Checker & Factorizer?
Open the tool, add your file (or paste your content), adjust any options, then press “Check number”. Your result is ready to download in seconds.
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