Fait mathématique: 4869 is a value of n for which 3n and 8n together use each digit exactly once.
Culture générale: 4869 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: April 30th is the day in 1900 that Casey Jones dies in a train wreck in Vaughn, Mississippi, while trying to make up time on the Cannonball Express.