Just for the sake of discussion with my colleagues, I calculated the number of lines of code in Community Edition. If my calculations are correct, it's in the ballpark of 6.5 million lines of Java, not counting Kotlin, etc.
That's impressive! If you don't mind sharing this info, how many lines of code are there in IDEA Ultimate? Preferably not including Android and PHP (these from the top of my head appear to be large chunks of code, though I may be mistaken). Hope it's not too difficult a question.