10 - summation of primes

#include <stdio.h>
#pragma hdrstop

#include <tchar.h>
//---------------------------------------------------------------------------

#pragma argsused

unsigned char is_number_prime(unsigned long  analyses_number, unsigned long  *prime_number_counter);
unsigned long long sum_prime_numbers(unsigned long  *prime_numbers, unsigned long  *prime_number_counter, unsigned long  max_number);

int _tmain(int argc, _TCHAR* argv[]) {

    unsigned long  test,analyses_number,index;
    unsigned long long sum_of_prime_numbers;
    unsigned long *prime_numbers;
    unsigned long  i;
    unsigned long  prime_number_counter;
    unsigned long  max_number = 2000000;
    unsigned long  start_point = 2;

    prime_numbers = (unsigned long  *) calloc(max_number, sizeof(unsigned long ));

    memset (prime_numbers, NULL, max_number);

    index = 0;
    prime_number_counter = 0;

    for (analyses_number = start_point; analyses_number < max_number; ++analyses_number) {

        if (is_number_prime(analyses_number, &prime_number_counter) == 1) {
            prime_numbers[index] = analyses_number;
            index++;
        }
    }

    sum_of_prime_numbers = sum_prime_numbers(prime_numbers, &prime_number_counter, max_number);

    return 0;
}
//---------------------------------------------------------------------------

unsigned char is_number_prime(unsigned long  analyses_number, unsigned long  *prime_number_counter) {

    unsigned long  counter = 0;
    unsigned long  i;

    for (i = 2; i < analyses_number; i ++) {
        if (analyses_number%i == 0)
            counter++;
    }

    if (counter != 0)
    {
        return 0; // not prime number
    } else {
        *prime_number_counter = *prime_number_counter + 1;
        return 1; // prime number
    }

}

unsigned long long sum_prime_numbers(unsigned long  *prime_numbers, unsigned long  *prime_number_counter, unsigned long  max_number) {

    unsigned long i;
    unsigned long long  sum_of_prime_numbers = 0;

    for (i = 0; i < max_number; ++i)
    {
        if (i < *prime_number_counter)
        {
            sum_of_prime_numbers = sum_of_prime_numbers + prime_numbers[i];
        }else
        {
            prime_numbers[i] = NULL;
        }
    }

    return sum_of_prime_numbers ;
}