/* www.programming9.com */ main() { int n, i; printf("Enter an Integer Number to Find PRIME or Not : "); scanf("%d", &n); for(i=2; i<=n/2; ++i) { if(n%i==0) { break; } } if(i>n/2) printf("%d is PRIME",n); else printf("%d is NOT PRIME", n); }

OUTPUT:

Enter an Integer Number to Find PRIME or Not : 23 23 is PRIME