Prime Number Calculator

A prime number is a whole number greater than 1 that cannot be exactly divided by any whole number other than itself and 1.

• The first few prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, and 29.
• The number 2 is the only even prime number.
• Any number that is not prime is called a composite number.

To check if a number is prime, this calculator uses an optimized trial division method. It checks for divisibility by 2, and then only by odd numbers up to the square root of the number being tested. This is much faster than checking every number.