math_fact: 2118 is a member of the Fibonacci-type sequence starting with 1 and 5.
trivia: 2118 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: October 18th is the day in 1967 that the Soviet probe Venera 4 reaches Venus and becomes the first spacecraft to measure the atmosphere of another planet.