general_fact: 16527 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 16527 is a boring number.
trivia: 16527 is an unremarkable number.
historical_date: March 31st is the day in 1146 that Bernard of Clairvaux preaches his famous sermon in a field at Vézelay, urging the necessity of a Second Crusade.