General fact: 21263 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 21263 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 21263 is a boring number.
Historical date: March 19th is the day in 1920 that the United States Senate rejects the Treaty of Versailles for the second time (the first time was on November 19, 1919).