5.To check wether a number is prime number or not

#include<stdio.h>
main()
{
int i,n,c=0;
scanf("%d",&n);
for(i=1;i<=n;i++)
{
 if(n%i==0)
c++;
}
if(c==2)
    printf("prime numbers:");
    else
    printf("not a prime numbers");
    return 0;
}