Fatto generale: 598 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 598 is 5^{1} + 9^{2} + 8^{3}.
Trivia: 598 is a boring number.
Data storica: August 20th is the day in 1998 that the Supreme Court of Canada rules that Quebec cannot legally secede from Canada without the federal government's approval.