general_fact: 5278 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 5278 is the number of ways, up to symmetry, to pick 3 elements of an 8×8 grid.
trivia: 5278 is an unremarkable number.
historical_date: June 13th is the day in 1977 that Convicted Martin Luther King Jr. assassin James Earl Ray is recaptured after escaping from prison three days before.