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Prime Number Checker
Check whether a number is prime, and get its prime factorization if not.
Free · No sign-up · Updated August 2026
97
is a prime number ✓
A prime number is divisible only by 1 and itself. For composite numbers, the prime factorization is shown.
🔒 This tool runs entirely in your browser. Your data is never uploaded.
Frequently asked questions
What makes a number prime?＋
A prime number is a whole number greater than 1 that is divisible only by 1 and itself. If a number isn't prime, this tool shows its prime factorization.
Is 1 a prime number?＋
No — 1 is neither prime nor composite. The smallest prime is 2, which is also the only even prime.