First, pointers are typically unsigned integers. Second, memory addresses are virtual, they don't have to exist physically. That is, you don't have to physicall

First, pointers are typically unsigned integers. Second, memory addresses are virtual, they don't have to exist physically. That is, you don't have to physically have up through 2 quintillion addressable bytes for a pointer with that value to be valid. This is especially true with Address Space Layout Randomization (ASLR) security techniques employed by operating systems. tl;dr: all valid pointer values are possible, regardless of how much memory you actually have.