Fatto generale: 6626 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 6626 is an uninteresting number.
Trivia: 6626 is an unremarkable number.
Data storica: February 20th is the day in 1933 that Adolf Hitler secretly meets with German industrialists to arrange for financing of the Nazi Party's upcoming election campaign.