The number 65,536 is an awkward figure to everyone except a hacker, who recognizes it more readily than his own mother's date of birth: It happens to be a power of 2—2 16 power to be exact—and even the exponent 16 is equal to 2 4 , and 4 is equal to 2 2 . Along with 256; 32,768; and 2,147,483,648; 65,536 is one of the foundation stones of the hacker universe, in which 2 is the only really important number because that's how many digits a computer can recognize. One of those digits is 0, and the other is 1. Any number that can be created by fetishistically multiplying 2s by each other, and subtracting the occasional 1, will be instantly recognizable to a hacker.