Fatto generale: 5778 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 5778 is the largest Lucas number which is also a triangular number.
Trivia: 5778 is an uninteresting number.
Data storica: October 26th is the day in 1967 that Mohammad Reza Pahlavi crowns himself Emperor of Iran and then crowns his wife Farah Empress of Iran.