You need 35 quadrillion in this currency to buy $1. Zimbabwe's quadrillionaires are about to disappear. The southern African country is finally mopping up what remains of its worthless currency by offering to swap bank deposits or cash for as little as one U.S. dollar per 35 quadrillion Zimbabwean dollars. Here is what that looks like in digits: $1 = Z$35,000,000,000,000,000.