Fatto generale: 6446 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 6446 is a boring number.
Trivia: 6446 is an unremarkable number.
Data storica: August 24th is the day in 1682 that William Penn receives the area that is now the state of Delaware, and adds it to his colony of Pennsylvania.