Fatto generale: 20651 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 20651 is an uninteresting number.
Trivia: 20651 is a boring number.
Data storica: July 15th is the day in 1799 that the Rosetta Stone is found in the Egyptian village of Rosetta by French Captain Pierre-François Bouchard during Napoleon's Egyptian Campaign.