This number has called me every week for the past several months.  If you call back, you get a message saying it's an invalid number.  Once when I answered an automated voice said "Goodbye" and hung up.  I answered another time and it was an automated spam message about nursing homes and senior care, I think.  I was too pissed off to actually pay attention.  I wish I could add myself to the no-call list, but I use my phone partially for business purposes and you're not allowed to register business numbers.