math_fact: 5533 is the number of graphs with 10 vertices and 2 cycles.
trivia: 5533 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: February 23rd is the day in 2007 that a train derails on an evening express service near Grayrigg, Cumbria, England, killing one person and injuring 22.