 # Prime Number and Composite Number

## Find out what is a Prime Number and Composite Number? Find out if a number is prime number or composite number

HomeMath

Prime Number

You can input a number and find if it is a prime number or composite number and the factors for the number.
1 is NOT A PRIME NUMBER.

## Prime and Composite Numbers • ### Prime Number Definition

Prime numbers are positive numbers that can only divisible by itself or by 1.In other words, the number which has exactly two factors 1 and the number itself is said to be a Prime number.
2 is a even prime number

• ### Prime numbers 1 to 100

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.

• ### Composite Number Definition

Composite Numbers are positive numbers that has more than two factors.In other words which can be written as multiplication of two or three numbers.

• ### Example of Composite Numbers from 1 to 100

4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 81,82, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 98, 99, 100.

## Steps to find the number is prime or not. • ### First method : Step 1

First divide the number by smaller prime numbers 2 , 3, 5 and so on..If we get a whole number then it cant be a prime number.

• ### Step 2

If we dont get the whole number as a result of dividing the number by prime numbers, then it is prime number.

• ### Example:

Check 8 is a prime or not.
Step 1: Divide 8 by 2 we get a result 4 and that is whole number so it fails to be a prime number.

Check 7 is a prime or not.
Step 1:Divide 7 by 2 we dont get whole number as result , repeat the process of dviding the number by next prime number 3 and still we dont get whole number as result again repeat by dividing 7 by 5 still it gives non whole number.since there is no factor before 7 we can conclude that 7 is a prime

• ### Second method : Step 1

Find all factors of the number

• ### Step 2

If the number has only two factors, then it is a prime otherwise it is composite number.

• ### Example:

Check 6 is a prime or not.
Step 1: Factors of six are 1, 2, 3 and 6.Since it has factors more than two it is not a prime number.

## What is Twin Prime? • ### Definition of Twin Prime:

Two prime numbers are said to twin prime if there difference is exactly two.

• ### Example:

(3,5) , (5,7) , (11,13) and so on..

• ### Is (2,3) a twin prime?

No, because two is a only even prime and their difference is not exactly two.

## Table of Numbers - Is It Prime or Composite Number? ## Frequently Asked Questions on Prime Number and Composite Number 