๐Ÿ”Ÿ Prime Checker

Is it prime?Yes, it's prime

Enter an integer and instantly find out whether it's a prime number. If it's not prime, its prime factorization is shown too. Useful for math homework or learning the basics behind cryptography.

How to use

  1. Enter the integer you want to check (0 to 1 trillion).
  2. Whether it's prime, and its prime factorization if not, are shown automatically.

FAQ

Is 1 a prime number?

No. By definition, a prime number is a natural number greater than 1 with no divisors other than 1 and itself, so 1 doesn't qualify.

How large a number can this check?

Integers up to 1 trillion (1,000,000,000,000) are supported. Larger numbers are excluded since the calculation would become too slow in a browser.

What happens if I enter a negative number or a decimal?

Primality is only defined for natural numbers 2 and above, so no result is shown for negative numbers or decimals.