What is zwanzig millionen worth in US dollars?

Answer 1

I assume you're referring to "zwanzig millionen Mark", i.e. 20 million marks. An amount that high on a German bill would only be from the Weimar Republic's hyperinflation period in the early 1920s. As such it hasn't been convertible into dollars for many decades, and in any case was only worth a fraction of a cent by the time the currency had effectively collapsed in late 1923.

These bills sell today mostly as curiosities. The major German site sammler.com lists 2 bills with that denomination; one issue is dated July 25, 1923 and the other is Sept. 1, 1923. Both currently retail for around €1, i.e. about $1.30.