General fact: 23404 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 23404 is an uninteresting number.
Trivia: 23404 is a boring number.
Historical date: January 28th is the day in 1958 that the Lego company patents the design of its Lego bricks, still compatible with bricks produced today.