Question: how many uuids are possible?
Answer: Each character can be a digit 0 through 9, or letter a through f. 32 hexadecimals x log2(16) bits/hexadecimal = 128 bits in a UUID. In the version 4, variant 1 type of UUID, 6 bits are fixed and the remaining 122 bits are randomly generated, for a total of 2¹²² possible UUIDs. We'll refer to this value as n.