【How-to】What is the smallest number for which an overflow can occur

This halves the number of possible positive values (roughly), so the largest number you can represent is 2^31–1=2,147,483,647, but instead of 0, the smallest number you can represent is -2,147,483,648. An unsigned 32-bit integer, by contrast, can represent anything from 0 to 4,294,967,295.