Write a program to check whether the entered number is prime or not.

Dr. A.P.J. Abdul Kalam Technical University, Lucknow

KCS101 / KCS201 Programming for Problem Solving - Using C Language

Lab Exercises

16. Write a program to check whether the entered number is prime or not.

/*

 File: Prgrm16.c

 Author: Aditya Saini

 Date: Sept 30, 2019

 Description: Program to check whether the entered number is prime or not.

*/

#include <stdio.h>

int main (void)

{

               int number;

               int i;

               //Input number.
               printf ("Input number: ");
               scanf ("%d", &number);

               //Checking if the number is prime or not.
               for (i = 2; i < number; i++)

               {
                              if (number % i == 0)
                              {
                                             printf ("%d is not Prime.", number);
                                             break;
                              }
               }
               if (i == number)
               {
                              printf ("%d is Prime.", number);
               }

               return 0;

};

Output

Input number: 23

23 is Prime.