General fact: 2786 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 2786 is the 9^{th} Pell-Lucas number.
Trivia: 2786 is an unremarkable number.
Historical date: August 17th is the day in 2008 that American swimmer Michael Phelps becomes the first person to win eight gold medals in one Olympic Games.