prime.c

prime.c

#include <stdio.h>
#include <math.h>

#define TARGET 1000000

int main() {
    long long found = 0;
    long long num = 2;
    while (found < TARGET) {
        long long till = sqrtl(num);
        long long i;
        for (i = 2; i <= till; i++) {
            if (num % i == 0) {
                break;
            }
        }
        if (i==till+1) {
            found++;
            found > TARGET - 5 || found % 1000000 == 0 ? printf("%lld: %lld\n", found, num) : 0;
        }
        num++;
    }
    return 0;
}

Apple M2 - 3.9s
i3-7100U @ 2.40GHz - 40s