How much is Zimbabwe worth?
It's GDP in 2010 was US$ 4.644 billion
It isn't worth much at all. Zimbabwe went through a period of hyperinflation to where it would take trillions of dollars simply to buy a dozen eggs. As such, their banknotes are mostly worthless and are traded just for laughs or as a sober reminder that all fiat currencies eventually collapse. Its worth a dollar or two at most if in perfect shape, and thats simply as a curiosity.
Here is a list of the top 5 richest people in Zimbabwe as of January 2014. Telecommunications mogul Strive Masiyiwa with a net worth of $829 million. Takudzwa Razemba in his early 20's has a net worth of $785 million. Nicholas Van Hoogstraten has a net worth of $729 million. Billy Rautenbach has a net worth of $568 million. Shingai Mutasa has a net worth of $142 million.
During its hyperinflationary period Zimbabwe issued a $21 trillion bill. However that was in Zimbabwe dollars, not US dollars, and was only worth a small amount. If you expand your question to other currencies, Weimar Germany printed a quadrillion-mark (1015 marks) note as a result of post-WWI hyperinflation. It too was worth only a tiny amount.