InfoUSA.com has the most thorough and reliable database of consumer information available. You can drill in further by segmenting demographic, psychographic and geographic variables. Always use any purchased lists with caution to make sure you adhere to the Do Not Call list. Further information can be found at: http://www.the-dma.org/government/donotcalllists.shtml

Have you looked at Twilio?

The legacy solution is InfoUSA. Not sure how good their data is anymore, but used to be solid a few years ago. Mellisa Data, relevategroup and a few others do this. Do a search for "Data Append" on google and scroll through the first few results. I'll have to dig it up but I think there are about 5 big ones in this space. Cost anything between 1-15 cents a pop.

I would imagine Trucaller is heading in that direction.