Mathematical fact: 2398 is the number of 3×3 sliding puzzle positions that require exactly 28 moves to solve starting with the hole in the center.
Trivia: 2398 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Historical date: July 25th is the day in 2000 that Air France Flight 4590, a Concorde supersonic passenger jet, F-BTSC, crashes just after takeoff from Paris killing all 109 aboard and 4 on the ground.