The highest denomination is currently $100. However, the US has had bills as high as $10,000 but they are no longer used.

Million dollar bills were never printed in the US. The highest denomination dollar bill that was printed in the US was the $100,000 dollar bill, produced in the 1930's. Woodrow Wilson was on this dollar bill, they are not printed anymore.

Yes.

Nope.

$100 is the largest in production.