Fatto generale: 457 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 457 is the index of a prime Euclid number.
Trivia: 457 is an uninteresting number.
Data storica: April 1st is the day in 1954 that President Dwight D. Eisenhower authorizes the creation of the United States Air Force Academy in Colorado.