general_fact: 15923 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 15923 is an unremarkable number.
trivia: 15923 is a boring number.
historical_date: August 5th is the day in 1600 that the Gowrie Conspiracy against King James VI of Scotland (later to become King James I of England) takes place.