Numbers with this prefix were first introduced in 2013.While 4156105110 was originally issued with the info above, the owner of the phone number (415) 610-5110 may have transferred it through a process called porting.
Caller type: Unknown
This number belongs to Craiglist. It's the number they send verification codes to when posting in adult sections. It works like this.
You contact the person or they contact you and you give your phone number
They create a new account for posting their spam c**p using your number for verification
You can get he call from Craigslist with the verification code
You pass on this verification code to the target and use it to confirm their posting
Well done, you have now allowed the spammer to create a new account using your phone number for verification. NEVER EVER give out a verification code received via this number.