[stevelosh]

If you were around in the 80's and 90's you might have already memorized the prime 8675309 (https://en.wikipedia.org/wiki/867-5309/Jenny). It's also a twin prime, so you can add 2 to get another prime (8675311).

[nlh]

My other favorite fun fact about this number (other than this new prime info which I am excited to have learned) is that in almost every store I’ve tried it, someone has used that (along with a local area code) as the phone number for a store loyalty card.

I’m a Bay Area guy, so if you’re ever at Safeway and need to get the discount without giving up your personal info, 415-867-5309 has got ya covered ;)

[pwg]

> someone has used that (along with a local area code) as the phone number for a store loyalty card.

Usually because for far too long, noisy retailers wanted a "phone number" upon checkout (even if one was paying cash -- Radio Shack was an especially bad one back in the day). For those who didn't want to get yet more telemarketing calls, repeating "Jenny's number" [1] from the song was a way to "just buy" whatever it was you wanted. The minimum wage cashier didn't care, but the cash register demanded "a number". So giving the cashier Jenny's number worked.

This has largely faded now that they can track everyone via one's credit card numbers.

[1] https://en.wikipedia.org/wiki/867-5309/Jenny

[fancy_pantser]

You can use the number with your local area code just about anywhere at the pump to get a gas discount as well (a common loyalty reward program benefit).

[jedberg]

I was around in the 80s, but this is awesome new information!

[out-of-ideas]

lol i didnt realize this was a prime number but i re-use this number any time i need a fake phone number in some sample/example data (im pretty certain nobody gets the reference, or takes the time to read it)