Hello everyone, i'm new to c++. I'm currently trying to make a program that finds the first prime above 1 billion, but i can't make it work. it just prints all numbers from 1 billon to infinity. This is my code:

Code:

#include <iostream>
#include <math.h>
using namespace std;
int prime(int n);
int main () {
int i;
for (i = 100000000;; i++) {
if (prime(i))
cout << "Dette er er det første primtal over 1 milliard: " << i << endl;
break;
}
cin.get();
return 0;
}
int prime(int n) {
int i;
double sqrt_of_n = sqrt(n);
for (i = 2; i <= sqrt_of_n; i++) {
if (n % i == 0)
return false;
}
return true;
}

I hope you can help me!