I received a call from 415-484-9507. Luckily I have caller ID at work. It's annoying that we can't block these calls but at least I don't have to answer them. :-)
automated message / computer caller
we have several phone lines at work that end in 1433, 1434, 1435, 1436 etc. and this number will call all the lines in 5 second increments. It is an automated message... don't bother answering.