Who called from 4156837147

Called came in on my cell. CID showed "1-415-683-7147". It's unusual for the "1" to show before the prefix.  I did not answer the call and no VM.

Called Friday 04/07/2017 at 9:07am.  Left no message.  However, when searching online this number popped up in "most looked up number today". (This may be some sort of scam.... 800notes.com seems to be the most informative regarding unknown calls.)