9 letters long
So why is a raven like a writing desk anyway?
The best answer that I’ve heard is, “Because Poe wrote on both.”
Well, that’s no fun. 
Oh. I instantly forgot that provision. Cancel my “denominator” entry.
punchline
Good one.
Nit picking premise of joke
But e is not complex. It is irrational but still real, complex mathematics involves i, the square root of -1.
Ah, see…This is why I hesitated to post the harder riddle. Nice job with "Camry,"though. Folks don’t usually get that one so fast.
Have I missed something here? Where’s the answer, dammit. Inquiring minds gots ta know. (I love these “think outside the box” riddles.)
I wrote a small Objective-C program to “stringify” all the numbers between zero and 1.2 million (using the NSNumberFormatterSpellOutStyle selector). And barring doing anything “cute” (like using “feet” or “dozen” or the like) there was no way to get a result with exactly nine characters and five vowels.
There were a couple of close-calls: “seventeen” has nine characters and four vowels, and “one million” has ten characters and five vowels.
However, the original problem did not include “y” as a vowel. If you add it, there were exactly two results that matched the all of the conditions.
I don’t know how to do the spoiler trick, but it is what you get by solving:
x^2 + 7371 = 172x.
Hint:
The answer contains no L, M, P, or T .
This riddle came to me a couple of weeks ago when I was at the dentist. I have always been nervous at the dentist office due to youth trauma too convoluted to explain here. In any case, In such situations I try to take my mind off off what is going on by trying to think up riddles and puzzles. This helps on nights with insomnia as well.
I remember thinking…“hey that’s a neat little riddle”… so I am glad the opportunity came along to post it. My sister is a computer science and math professor at Appalachian State. I think I will e-mail it to her and see if she is stumped as well.
What is the number of a Saturday night traffic stop?
It was funnier before you translated it to English.
Yes indeed.
They both have inky quills.
They both slope with a flap.
Because they both have 14 k of g in a f p d.
What do you get when you cross a Pacman character with a porcupine?