Fatto generale: 2851 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 2851 is an unremarkable number.
Trivia: 2851 is a boring number.
Data storica: October 21st is the day in 1959 that President Dwight D. Eisenhower signs an executive order transferring Wernher von Braun and other German scientists from the United States Army to NASA.