Fatto generale: 45707 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 45707 is an unremarkable number.
Trivia: 45707 is an uninteresting number.
Data storica: February 20th is the day in 1792 that the Postal Service Act, establishing the United States Post Office Department, is signed by President George Washington.