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).
By Conrad Hackett17 comments. As of this month, the worldâs population is now 7.2 billion, according to the United Nations, which celebrates World Population Day today. According to U.N. data, half of the people around the globe (3.6 billion) live in just a half-dozen countries. China has the worldâs largest population (1.4 billion), followed by India (1.3 billion). The next most-populous nations â the United States, Indonesia, Brazil and Pakistan â combined have less than 1 billion people. The demographic future for the U.S. and the world looks very different than the recent past.