General fact: 84838 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 84838 is an unremarkable number.
Trivia: 84838 is an unremarkable number.
Historical date: April 11th is the day in 1951 that the Stone of Scone, the stone upon which Scottish monarchs were traditionally crowned, is found on the site of the altar of Arbroath Abbey.