Fatto generale: 21802 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 21802 is a boring number.
Trivia: 21802 is a boring number.
Data storica: September 9th is the day in 1513 that James IV of Scotland is defeated and dies in the Battle of Flodden Field, ending Scotland's involvement in the War of the League of Cambrai.