Fatto generale: 20663 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 20663 is a boring number.
Trivia: 20663 is an uninteresting number.
Data storica: July 27th is the day in 1990 that the Supreme Soviet of the Belarusian Soviet Republic declares independence of Belarus from the Soviet Union.