67 termial (stylised as 67?) is a number command in reference to the computer science term termial.
If you get kind of confused while typing "67", you may think about adding an "?". However, this would create the number 67 termial, 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 question mark following a number typically represents a termial equation, meaning you actually typed 1+2+3...+67, so you actually typed 2278." with the reaction of a "🤓" emoji.