Prime Numbers
Prime numbers are those whole numbers that have only two factors- one and the number itself. This means that the number can be divided by itself and the number one. For example, 2, 7, 31, 37, etc.

Facts about prime numbers
The only even prime number is 2.
1 is neither prime nor composite number.
No prime number greater than 5 has the last digit 5.
Activities to memorize prime numbers
Recite a few numbers in class and ask students to classify them as prime and not prime.

A prime number is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself.