This is the Gmail (google mail) verification system phone number. When you sign up with gmail they send you the activation code by SMS from this number (at least I got mine from there). Possibly someone mistyped their phone number while activating gmail account.
This is a legitimate verification code sent out by the Google company's Gmail email service when establishing new accounts. It means someone (possibly by mistake) typed your phone number in as a contact number for a new Gmail account. it's a legitimate company but the phone may have been typed in by error (typo). I am a public librarian and I occasionally use the library's number to help patrons verify new accounts when they do not have a cell phone, so I have gotten several texts from this number.