Prime number programme in c

A prime number is a natural number that is divisible by only one and itself

Example of prime number

2 3 5 7 etc

Example of prime number programme in C

// Online C compiler to run C program online
#include <stdio.h>

int main( ) 
{ 
int n,flag=0;
 printf("enter any number\n");
 scanf("%d",&n);
 if(n<1){
     printf("number is not prime number");
 }
 else{
     for(int i=2;i<=n/2;i++){
         if(n%i==0){
             printf("number is not prime");
             flag++;
             break;
         }
         
     }
     if(flag==0){
         printf("number is prime");
     }
 }
 return 0 ; 
}

An output of this prime number programming in c

enter any number
3
number is prime

In the above prime number programming in c first we have declared int n variable that will store the user input. we know that prime numbers are natural number and it should not be divisible by 1 and itself so in for loop we have used i=2 and i<=n/2 to check prime number