What is the highest number that has been counted called?

The biggest named number is googolplex, ten to the
googol power, or 10^10^100, written as a one followed by googol zeroes.

samantha

The googol or googolplex is not distinguished by the assumed fact that it is the highest number ever "counted." The googol is simply the number 1 followed by one hundred zeros, and the googolplex, as pointed out, is 10^googol. The googol was named by the nine-year-old nephew of Dr. Edward Kasner, who was asked to think up a name for a very big number, namely, 1 with a hundred zeros after it. At the same time that he suggested "googol" he gave us the name for a still larger number: "googolplex." It was first suggested that a googolplex should be 1, followed by writing numbers until one got tired. And, this remained as the definition of for the googolplex for quite some time. Finally, someone decided that it would be appropriate to give the term a more definite meaning, one that indicated an incredibly enormous number, but would also incorporate the googol in its description. So was born the number: 10 to the power of googol.

Thanks!

The greatest named number is Graham's Number. Look here.