There are other countries that use dollars for their currency. At least one, Zimbabwe, experience hyperinflation and probably had a million dollar bill at one time, although I have no idea if it is still legal tender. Even if you had one it would be essentially worthless. When I got a 100 trillion dollar Zimbabwe bill they were being given away to anyone who went into a local coin store.
I do not know of any countries currently using million dollar bills, but they might exist somewhere.
No, the largest US note ever printed was $10,000. But currently, $100 is the biggest.
probs not lol
no.