Write a C Program to check whether a number is Prime or not

Source Code :

#include<stdio.h>

void main()

{

      int n,i,fl=0;     //Declaration of variables

      clrscr();

      printf("\nEnter a Number : ");

      scanf("%d",&n);   //Initialization of number from user

      for(i=2;i<n;i++)    //For Loop for checking prime number

      {

            if(n%i==0)  //Checking if the number can be divided

            {                        //by any other number other

                  fl=1;

            }

      }

      if(fl==1)   //Checking for result

            printf("\n%d is Not a Prime Number ",n); //Display Result

      else

            printf("\n%d is a Prime Number ",n);

      printf(“\nPress any Key to Continue………”);

      getch();

}

Output :

Enter a Number : 11

11 is a Prime Number 

Press any Key to Continue……

Enter a Number : 4

4 is Not a Prime Number

Press any Key to Continue…………