Why is the number one not a prime?

Frequently asked questions about primes
(from the Prime Pages' list of frequently asked questions)

GIMPS found two new primes: 2^43112609-1 (about 12.9 million digits, Aug 08) and 2^37156667-1 (only 11.1 million digits, Sept 08).

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Here is a list of questions and answers for many of the frequently asked questions at this site. If you have difficulty finding what you want, you might try searching through the site.

The definition of prime:
Basic properties of primes
Lists and records
- What are the first
  - 1,000 Primes? (about 7k)
  - 10,000 Primes? (about 72k)
  - 100,008 Primes? (about 822k)
  - other lists of primes
- What is the
- What is the longest list of primes?
- Where is a list of the x-digit primes?
- I need a few small primes (say 10 to 300 digits)
Mersenne Numbers
- What are the known Mersenne primes?
- What are the decimal expansion of the Mersenne numbers? (and how do you "say" these numbers?)
- Where is the next Mersenne prime?
Miscellaneous
- What is the probability that gcd(n,m)=1?
- Why do people find these big primes?
Questions from those who find primes:
Questions from those who have proved something new
- I have a new result, what do I do with it?

Another prime page by Chris K. Caldwell <caldwell@utm.edu>