Fatto generale: 11220 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 11220 is an unremarkable number.
Trivia: 11220 is a boring number.
Data storica: September 19th is the day in 1961 that Betty and Barney Hill claim that they saw a mysterious craft in the sky and that it tried to abduct them.