german banknote help

German hyper inflation note 2 million Marks.

10,000,000 inflation marks; issued 8/22/1923, recalled and exchanged from 10/1/1923 as written on the note. Inflation notes were later replaced by the Rentenmark.

If I remember correctly, in the "MM-51" MM is a symbol of the company that printed the note (they were printed in many locations), 51 is 51st series.

Generally, this type is common. Inflation notes often have different watermarks - someone would have to check the books if there are any valuable varities.