20 000 000 000 Mark Landesbank der Rheinprovinz

The Landesbank der Rheinprovinz was a Prussian provincial institution, not a central bank, yet during the hyperinflation of 1923 it joined dozens of German regional banks, municipalities, and industrial firms in issuing Notgeld simply to keep commerce functioning. The Reichsbank could not print fast enough. J. P. Bachem, a Cologne-based Catholic publishing house with a long printing history, was a practical local choice — proximity mattered when denominations were being revised weekly and transport delays could render a shipment worthless before it arrived.

Twenty billion marks. By late 1923, that figure bought roughly a loaf of bread.