Fatto matematico: 903 is the 6^{th} super Catalan number.
Trivia: 903 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: June 21st is the day in 1948 that Columbia Records introduces the long-playing record album in a public demonstration at the Waldorf-Astoria Hotel in New York, New York.