Matt Cutts from Google went on record on those sites that rank well for all those random phone numbers, the ones that simply list thousands of phone numbers on a single page. He said it is spam, keyword stuffing and is against Google's guidelines.
Matt Cutts said:
“I wanted to clarify a quick point: when people search for a phone number and land on a page like the one below, it's not really useful and a bad user experience. Also, we do consider it to be keyword stuffing to put so many phone numbers on a page.
There are a few websites that provide value-add for some phone numbers, e.g. sites that let people discuss a specific phone number that keeps calling them over and over. But if a site stuffs a large number of numbers on its pages without substantial value-add, that can violate our guidelines, not to mention annoy users.”
“These pages have always been considered violations of our guidelines as keyword stuffing. I just wanted to be especially clear so that we could point to explicit guidance we'd given.”

