So I just heard about the new prime number that was discovered and for some reason got kind of interested in it. So I'm looking at prime number tables on various webpages that show the prime numbers, dates discovered, etc. I'm confused on what the "digits" column in these tables means. For example, the prime number 5 has 2 digits, and the prime number 13 has 4 digits. What are these digit numbers? How do you get 2 digits from the prime number 5? Thanks.