If it is an unsigned 4-byte integer, only 2 32-1can be stored at most. If it is greater than this number, it will overflow. However, due to the difference of binary, it doesn't mean that everything greater than this limit is this limit. Let's take a smaller example.

Suppose a 4-bit binary number (0000 ~11,unsigned) can store 16 numbers from 0~ 15. If a 20:

The binary of 20 is 10 100 (note that it is a 5-bit binary). If you put four digits, the leftmost 1 will be thrown away because it can't fit. So what is actually stored is 0 100, which is decimal 4.