Fatto generale: 5641 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 5641 is a boring number.
Trivia: 5641 is a boring number.
Data storica: June 11th is the day in 1972 that the Eltham Well Hall rail crash, caused by an intoxicated train driver, kills six people and injures 126.