general_fact: 16039 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 16039 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 16039 is an uninteresting number.
historical_date: November 29th is the day in 1944 that the first surgery (on a human) to correct blue baby syndrome is performed by Alfred Blalock and Vivien Thomas.