This is a number used by the Skype computer phone service.  I know because I called my house to check my messages and this is the number it came in on.  The calls you are getting are probably from other Skype users around the world either trying it out or simply making a missdialed call.  In any case it is not a number you can call back.
If somebody is harassing you, then contact Skype at http://support.skype.com/en_US/support_request?  and enter an abuse ticket.