The worlds longest prime number is discovered

A researcher at the University of Central Missouri has discovered a massive number, 2 to the power of nearly 58 million minus 1, which is over 17 million digits long. Printing this number would require more than 10 packs of A4 paper, and writing it by hand would take at least a year.

What is the power of the number that the researcher calculated?

If the number were written out by hand, how long would it take?