# Prime Number Program in Java

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In the following question, we are supposed to write a Java Source Code to ask the user for an Integer input and check if the number is a Prime Number.

Prime number are those numbers who have only two factors: 1 and the number itself.

**Example:** 1,2,3,5,7,11,13,etc are some examples of Prime Number.

The standard algorithm will be:

- Enter and Store the Integer Input from the user.
- Run a For-Loop from 1 to N.
- At every iteration of the loop, check if the value of the iteration completely divides the integer input.
- If the result is true, the counter variable is incremented.
- After the loop terminates, check if the value of the counter variable is 2 or not, which means there are only two factors for the N.
- Print the Result accordingly.

### Source Code:

`/* Program to check if a number is Prime or Not*/ import java.util.*; class PrimeNumber { public static void main() { Scanner inp=new Scanner(System.in); System.out.print("\n Enter Number: "); int n=inp.nextInt(); int i,c=0;`

for(i=1;i<=n;i++) { if(n%i==0) //Checking if there are two factors of the number. c++; }

if(c==2) System.out.println(n+" is a Prime Number"); else System.out.println(n+" is not a Prime Number");

`} }`

### Output:

`Enter Number: 2 2 is a Prime Number`

Enter Number: 36 36 is not a Prime Number

`Enter Number: 101 101 is a Prime Number`