The hyperinflation occurs when a country experiences very high and usually accelerating rates of inflation, rapidly eroding the real value of the local currency, and causing the population to minimize their holdings of the local money.
The largest denomination banknote ever officially issued for circulation was in 1946 by the Hungarian National Bank for the amount of 100 quintillion pengo ( or 10 followed by 20 zeroes).
This was during the hyperinflation in Hungary (1945-1946). It also held the record for the highest monthly inflation rate ever – 41,900,000,000,000,000,000 % which meant prices doubled every 15.3 hours. To put this in perspective, U.S. inflation rate is 2%, optimum inflation rate is generally agreed to be 1-3% and a country is said to enter hyperinflation if the inflation rate exceeds 50% (and these are yearly inflation rate values).