Fatto matematico: 1712 is the number of regions the complex plane is cut into by drawing lines between all pairs of 16^{th} roots of unity.
Trivia: 1712 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: September 7th is the day in 2011 that a plane crash in Russia kills 43 people, including nearly the entire roster of the Lokomotiv Yaroslavl Kontinental Hockey League team.