#include<iostream.h> #include<conio.h> void main () { clrscr(); int n,i,x=0; cout << "enter any number" << endl; cin >> n; for(i=2;i<n;i++) { if(n%i==0) { x++; } } if(x==0) { cout << "prime" << endl; } else { cout << "not prime" << endl; } getch(); } Output: enter any number 3 prime