c program to find whether the given number is prime or not ?

In this C program, we will input the number when program runs and find whether that entered number is prime or not. This program uses "%" or "modulus" operator which gives the remainder of two numbers when it is divided. For example : 7 % 2 = 1, as 1 is remainder when 7 is divided by 2. So if the number is not prime then its % operation will give output '0' otherwise it is prime. Let us see how this program is implemented.

#include<stdio.h>                     // Including library
#include<conio.h>

int main()                              
{
     int n;
     int i;
     printf(" enter the number : ");   
     scanf("%d",&n);                  
     for(i=2; i<n; i++)
     {
              if(n%i==0)              
               {
                printf("%d is not a prime number.", n);
               getch();                                                  // hold  the  screen to display the above message
               return (1);                                              // return statement  will return the value and terimate
               }
     }
printf("%d is a prime number.", n);
getch();
}
         

Lets see the output of this program

output : Program to find prime number 

Here’s the another  program to find whether  the given number is prime or not by using recursion function.

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