math_fact: 47811 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 47811 is an unremarkable number.
historical_date: November 25th is the day in 1343 that a tsunami, caused by the earthquake in the Tyrrhenian Sea, devastates Naples (Italy) and the Maritime Republic of Amalfi, among other places.