With help from the interweb
  1. Add the numbers between 2 and 7 and you get 27 (2+3+4+5+6+7)
  2. It's the age Kurt Cobain, Brian Jones, Jim Morrison, Janis Joplin, and Jimi Hendrix all died. Amy winehouse and basquiat as well.
    @anneclark contributed Amy and @rachel contributed basquiat
  3. A Rubik's cube has 27 pieces including its core (counting as one)
  4. It's the number of ingredients in Rick Bayless's black mole sauce
  5. Each team in baseball has 27 outs per game
  6. The ascii code for the escape key is 27
  7. The number of straight lines on any cubic surface is 27
  8. 27 is the only positive number that is 3 times the sum of its digits (2+7)*3=27
  9. It's 3 to the power of 3, 3 cubed to its friends
  10. It's my wife's favorite number
  11. There are 27 bones in the human hand ✋🏼
    Suggested by @michelle