Fatto generale: 20606 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 20606 is an uninteresting number.
Trivia: 20606 is a boring number.
Data storica: May 31st is the day in 1991 that Bicesse Accords in Angola lay out a transition to multi-party democracy under the supervision of the United Nations' UNAVEM II mission.