Generally:
You'll study this for years before you have a satisfying answer. The number 23 is prevalent throughout all media. Granted sometimes randomly, but astoundingly so often that you'll be forced to continue wondering why.
Seek the answer for yourself. As far as I can tell, it's 100% attached to darkness / cult symbolism (mockery).
Q's use:
Always multiple meanings. US Codes, countdowns etc.
Lastly, if you begin looking, you'll find 236, 239, 234 across a ridiculous amount of media. The 9 is flipped to form a 6, the 4 is also flipped to form a 6.
These people are evil. Only study the darkness from a place of light.
Godspeed.