The hexadecimal number of 90021 is:
The hexadecimal number represents numbers in a system to the base of 16. There also exist alphanumeric digits (a-f) in addition to the known numbers of the decimal system (0-9).
Also, the hexadecimal system is widely used in computer science as a number system because it simplifies the handling of the binary system of numbers. This simplification arises because 16 is a power of 2 (dual system) and thus can be a very easy converted.
The numbers of the dual system represented as a number in the hexadecimal system ensure a higher readability for humans, as their size can be estimated and the number itself much less digits.