Fatto generale: 1782 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 1782 is the smallest number n that is 3 times the sum of all the 2-digit numbers that can be made using the digits of n.
Trivia: 1782 is an uninteresting number.
Data storica: November 16th is the day in 1988 that the Supreme Soviet of the Estonian Soviet Socialist Republic declares that Estonia is "sovereign" but stops short of declaring independence.