general_fact: 28577 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 28577 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 28577 is an unremarkable number.
historical_date: March 28th is the day in 1979 that the British House of Commons passes a vote of no confidence against James Callaghan's government, precipitating a general election.