Developer`$MaxMachineInteger

$MaxMachineInteger gives the maximum integer that is represented internally as a single atomic data element on your computer system.

$MaxMachineInteger is typically on a computer system that is referred to as an -bit system.

Arithmetic operations involving integers smaller than $MaxMachineInteger are typically faster than those involving larger integers.

See also: MachineIntegerQ, $MaxMachineNumber, $MachinePrecision.