The maximum length of the number of a credit card can be 19 digits, and the length of the account field can maximum be 12 digits. Each issuer can have a trillion possible numbers of an account. The final digit on a credit card number is a check one, similar to a checksum. It confirms the initial digits of the number and prevents the attempts to invent card numbers.
Longest lasting empire in history. The Roman Empire is considered to have been the most enduring in history. The formal start date of the empire remains the subject of debate, but most historians agree that the clock began ticking in 27 BC, when the Roman politician Octavian overthrew the Roman Republic to become Emperor Augustus.
And do. Greece has a pretty good claim having invented the concept in the first place. However, long spells as an Ottoman colony or under military junta might put it out of the running if you're looking for longest continuously democratic country. Britain has a decent claim but it depends what you mean by democracy. As Rowan Atkinson put it in Blackadder: take Manchester for instance.