Fatto matematico: 849 is a value of n for which s(n-1) = s(n+1).
Trivia: 849 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: April 28th is the day in 1978 that President of Afghanistan, Mohammed Daoud Khan, is overthrown and assassinated in a coup led by pro-communist rebels.