67 factorial (stylised as 67!) is a number command in reference to the mathematical term factorial.
If you get very excited while typing "67", you may think about adding an "!". However, this would create the number 67 factorial, which is very different from normal 67. When you type this, you will get your normal old 67 response, but you will also be greeted with the message, "Also, I hope you know using the exclamation mark following a number typically represents a factorial equation, meaning you actually typed 1×2×3...×67, so you actually typed 36471110918188685288249859096605464427167635314049524593701628500267962436943872000000000000000." with the reaction of a "🤓" emoji.