general_fact: 52517 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 52517 is an unremarkable number.
trivia: 52517 is an uninteresting number.
historical_date: October 14th is the day in 1940 that Balham subway station disaster, in London, England, occurs during the Nazi Luftwaffe air raids on Great Britain.