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 island in the world â according to the Guinness Book of Records â is Bishop Rock. It lies at the most south-westerly part of the United Kingdom. It is one of 1040 islands around Britain and only has a lighthouse on it. In 1861, the British government set out the parameters for classifying an island.