How to tell if a number is prime or composite?
Composite numbers can be defined as natural numbers that have more than two factors. In other words, a number that is divisible by a number other than 1 and the number itself is called a composite number.
Answer: If a number has more than two factors (1, itself) it is a composite number, else it is said to be a prime number.
Prime numbers are the numbers that have only two factors, that are, 1 and the number itself.
Let us look at 6 and 7 as examples.
The number 6 has four factors i.e,1, 2, 3, and 6 whereas, the number 7 has two factors i.e, 1, and 7.
So, 6 is a composite number while 7 is a prime number.