hexadecimal number
A number represented in base 16. The right-most digit is multiplied by 16 to
the power of zero. The digit immediately to the left is multiplied by 16 to the
first power. The digit immediately to the left of that is multiplied by 16 to
the second power, and so on. The characters that represent a hexadecimal number
are 0-9 and A-F (for 10-15).