A Prime number is a natural number (counting number) that can be divided only by 1 or itself.
Like the numbers; 2,3,5,7,9
3 can only be divided by 1 or itself, hence, it is a prime number.
6, can be divided by 1,2,3, hence, it is NOT a prime number, rather, it is called a composite number
-2 is the only even prime number.
-0 and 1 aren't considered as prime numbers.