I just got a call from this number.  I did not answer and they did not leave a message.   Since they did not leave a message I assume they are telemarketers and so I have added this number to my blocked call list.  

My phone number has been on the National Do Not Call Registry since August 2003 so if they are telemarketers, they are violating the law.

To block calls like this I got a Panasonic KX-TGE245B that allows me to block up to 250 numbers and/or area-codes.  Panasonic has several new 2014 models that will block that many numbers.  You simply save the CID to the blocked list.  You can also block area codes by adding them to what they call a “Range List” (you are blocking the range of numbers starting with that area code).