358205873110913227 =    380003149 * 942639223    took 0.01s
  195482582293315223 =    242470939 * 806210357    took 0.0021s
  107179818338278057 =    139812461 * 766597037    took 0.0023s
   44636597321924407 =    182540669 * 244529603    took 0s
  747503348409771887 =    865588487 * 863578201    took 0.016s

// GCC 128-bit extension available output :
170141183460469231731687303715506697937 =
13602473 * 230287853 * 54315095311400476747373 took 0.137699s

2139508543525359760856377898747 = 18122728927937 * 118056643236947131 took 17.2946s
2080913777018885818418638213057 = 283954641807703 * 7328331608778919 took 40.8842s

// 64-bit source code is here.

#include <stdio.h>

int main(void) {
    // allocate memory for 64 factors.
    positive_number *array = calloc(64, sizeof(positive_number));

    positive_number n = 7806418495977353572 ;

    size_t n_factors = factor(n, array) - array ;
    printf("There are %zu factors of %llu : \n", n_factors, n);
    for(int i = 0; array[i]; ++i)
        printf("- %llu\n", array[i]);
    free(array);
}