How do you say 10000000000000000000000000000?

The number 10,000,000,000,000,000,000,000,000,000 is referred to as "ten octillion" in the short scale system used in the United States and most English-speaking countries. In the long scale system, which is used in some parts of Europe, it would be called "ten thousand quadrillion." The naming convention varies based on the numerical system in use.