Fatto generale: 42013 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 42013 is an uninteresting number.
Trivia: 42013 is an unremarkable number.
Data storica: January 10th is the day in 1863 that the London Underground, the world's oldest underground railway, opens between London Paddington station and Farringdon station.