Fatto matematico: 6819 is 20457 / 3, and each digit is contained in the equation exactly once.
Trivia: 6819 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: September 1st is the day in 1920 that the Fountain of Time opens as a tribute to the 100 years of peace between the United States and Great Britain following the Treaty of Ghent.