math_fact: 636 is a number n whose 5^{th} root has a decimal part that begins with the digits of n.
trivia: 636 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: September 27th is the day in 2008 that CNSA astronaut Zhai Zhigang becomes the first Chinese person to perform a spacewalk while flying on Shenzhou 7.