Fatto matematico: 2135 is a value of n for which s(n-1) + s(n+1) = s(2n).
Trivia: 2135 is a boring number.
Data storica: November 4th is the day in 1852 that Count Camillo Benso di Cavour becomes the prime minister of Piedmont-Sardinia, which soon expands to become Italy.