Fatto generale: 13778 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 13778 is an unremarkable number.
Trivia: 13778 is an uninteresting number.
Data storica: September 20th is the day in 2011 that the United States ends its "Don't Ask, Don't Tell" policy, allowing gay men and women to serve openly for the first time.