Fatto generale: 20789 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 20789 is an uninteresting number.
Trivia: 20789 is an unremarkable number.
Data storica: November 30th is the day in 1993 that U.S. President Bill Clinton signs the Brady Handgun Violence Prevention Act (the Brady Bill) into law.