Fatto matematico: 548 is the maximum number of 9^{th} powers needed to sum to any number.
Trivia: 548 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: July 1st is the day in 1968 that the Nuclear non-proliferation treaty is signed in Washington, D.C., London and Moscow by sixty-two countries.