The largest known Wilson prime.
Reggie Jackson hit 563 home runs in his professional baseball career. He led his teams to five world championships and eleven division titles.
As Pierre Cami points out, this is the smallest prime with
a twin Carmichael number, since 563 - 2 = 561 is the first
Carmichael number. [Post]
The smallest prime happy number with a prime happy numbered index. [Goelz]
Popular Mechanics sells "The Pocket Genius: 563 Facts That
Make You the Smartest Person in the Room."
(There are 2 curios for this number that have not yet been approved by an editor.)