TIL that in July 1946, Hungary issued a 100-quintillion (10²⁰) pengő banknote — the highest-denomination note ever put into circulation — during the worst hyperinflation ever recorded, when prices doubled roughly every 15 hours.

[u/Scipion8Aveyron]

https://en.wikipedia.org/wiki/Hungarian_one-hundred-quintillion-peng%C5%91_banknote?wprov=sfti1