This help book in the Language Reference book covers the following information:

The functions in this chapter are used for bit manipulation and base conversion for unsigned 32-bit values.  These values are often passed to and returned by Windows API and other DLL functions.  Interpreting such values often requires analysis and manipulation of individual bits.

For all parameters designated as 32-bit integers, non-integers will be truncated to integers. For integers larger than 32 bits, only the least significant (right-most) 32 bits are used.