Prime Number Checker

Instantly check if a number is prime and find its smallest factor if it's composite.

Results

Calculated values for Prime Number Checker will appear here

Ready for Integer Audit...

How it Works

Enter a positive integer. The calculator uses trial division up to the square root of the number to determine if it has any divisors other than 1 and itself.

Formula

A prime number has exactly two distinct positive divisors: 1 and itself.

Frequently Asked Questions