Fatto generale: 10040 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 10040 is an unremarkable number.
Trivia: 10040 is a boring number.
Data storica: June 27th is the day in 1991 that Slovenia, after declaring independence two days before is invaded by Yugoslav troops, tanks, and aircraft starting the Ten-Day War.