general_fact: 4018 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 4018 is an uninteresting number.
trivia: 4018 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: December 31st is the day in 535 that Byzantine General Belisarius completes the conquest of Sicily, defeating the Ostrogothic garrison of Syracuse, and ending his consulship for the year.