Why is (unsigned long)1073741824 * 8 = 0?

Question

C++ / C#

At the moment, the variable "Factor" is 1073741824. When I try to multiply it by 8, I get 0.

I tried this: (unsigned long)1073741824 * (double)8 or (unsigned long)1073741824 * 8.0 , everything works, but the result is a floating point number , but I need an integer.

Tell me why is that? How can I fix it?

unsigned long faktor = 1073741824;
faktor = faktor * (unsigned long)8;

Answer 1

unsigned long - 2 ³² -1 = 4'294'967'295
​​1'073'741'824 * 8 = 8'589'934'592, which is greater than the maximum value for this type.
Use unsigned __int64 or unsigned long long if available on your system.