how to determine prime number

this program will determine whether input is prime number or no, whats is prime number.

prime number is a natural number that has exactly two distinct natural number divisors: 1 and itself.

this is program how to determine prime number....

<br /> #include <iostream><br /> #include <stdlib.h><br /> <br /> using namespace std;<br /> <br /> int main(int argc, char *argv[])<br /> {<br /> <br /> int bil,s,cek,f;<br /> cout<<"Masukkan bilangan : "; cin>>bil;<br /> <br /> for(s=1;s<=bil;s++) { cek=0 ; for(f=1;f<=bil;f++) { if(s%f==0) {cek++;} } } if(cek==2) {cout<<bil<<" merupakan bilangan prima \n";} else {cout<<bil<<" bukan bilangan prima "<<endl;} system("PAUSE"); return 0; }

final result in dev :