The Largest Prime Number

Mathgeek asks:

What is the largest known prime number?

Drew sez:

In case my readers don't know what a prime number is, a prime number is a number that can be divided only by two numbers, 1 and the number itself. There are a whole lot of prime numbers out there--1, 2, 3, 5, 7, 11, 13 ... the list goes on. And on.

And on.

In fact, it goes on so far that the largest known prime number is longer than most books! The first few digits are:

316,470,269,330,255,923,143,453,723,949,
337,516,054,106,188,475,264,644,140,304,
176,732,811,247,493,069,368,692,043,185, ...

... and that's just the start! It goes on for hundreds and hundreds of pages. You can download the entire number here, but I wouldn't, since it would take you nearly an hour for the file to download. In fact, it's almost 13 million digits long!