I do not have anything to do with phone companies etc; I do research in computer security, and this is just a random service for/of/by the Internet community. See also the listing by state/country and the NANPA data. There are also several other listings on the web.
If you're younger than 50, your 2012 contributions to a traditional IRA or a Roth IRA are limited to $5,000 or the total of your taxable compensation, whichever is smaller.
Between 59-1/2 and 70-1/2, you can choose whether or not you want to access your retirement funds. You do not have to take any withdrawals; in fact, you can begin depositing more on an annual basis once you reach age 50. This age is a good time to really increase the money in your accounts.