Following the third, fourth, or fifth digit, every number up through 15 is the account number while that final number, 16, is the check digit. All Discover cards start with the number six and are 16 digits in length, while petroleum cards start with the number seven and airline cards start with the number one.
Vatican City. Vatican City â 0.2 square miles â The worldâs smallest state, the Vatican has a population of 770, none of whom are permanent residents. The tiny country which surrounds St. Peterâs Basilica is the spiritual center for the worldâs Roman Catholics (over 1 billion strong).
The smallest nation is Vatican City, which has a population of under 1000 and has a Swiss Guard regiment of 110. Nauru is also fairly small, having a population of 10000 and 23 guns among 100 police officers. If the country from 1000 years ago were placed geographically adjacent to the modern one, the country from 1000 years ago would definitely win. There is only so much ammo the Swiss guards ...