Input
Output
#include <iostream> using namespace std; int main() { int n = 4, i, flag = 0; cout << "Enter the number: " << n << endl; for(i = 2; i <= n/2; i++) { if(n%i == 0) { flag = 1; break; } } if ( n<=1) { cout << "Prime number is greater than 1."; } else { if (flag == 0) cout << n << " is a prime number." ; else cout << n << " is not a prime number." ; } }