general_fact: 9723 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 9723 is a value of n for which n and 5n together use each digit 1-9 exactly once.
trivia: 9723 is a boring number.
historical_date: August 14th is the day in 1816 that the United Kingdom formally annexed the Tristan da Cunha archipelago, ruling them from the Cape Colony in South Africa.