Fatto generale: 8542 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 8542 is a boring number.
Trivia: 8542 is an unremarkable number.
Data storica: May 21st is the day in 1924 that University of Chicago students Richard Loeb and Nathan Leopold, Jr. murder 14-year-old Bobby Franks in a "thrill killing".