I've received six calls from this number in the past week, which is in my local area code. They are calling my mobile phone and never leave a message. Since I did not find anything on this site yet, I'm logging it now. When I attempt to call it back (from another phone with caller id blocked) I get a "your call did not go through" message and error code.

Probably spoofed like all the other unknown callers. I've now blocked it too.

Thank you for trying and reporting for the rest of us!  I will make sure to check 800 before answering calls from an 831 number since I, too, am in CA, although So Cal.  Have a Happy New Year.

Left no message! Blocked Number!