Thread: problem with large integers

The small program below calculates factorials -but it works only up to 25. For input >=26 I get errors. How can I use bigger integers?

Code:

#include <stdio.h>
int main()
{
  int c, n ;
  long long factorial=1;
  printf("Enter a number to calculate it's factorial\n");
  scanf("%d", &n);
  for (c = 1; c <= n; c++)
    factorial = factorial * c;
  printf("Factorial of number %d = %lld\n", n, factorial);
}