Fatto matematico: 2974 is a value of n for which s(n) = s(n+1).
Trivia: 2974 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: February 21st is the day in 1804 that the first self-propelling steam locomotive makes its outing at the Pen-y-Darren Ironworks in Wales.