I have called the number back. It says thank you for calling back to be removed from the list press 2 and when you do it hangs up. I have the comcast app on my phone so I can see when my house phone rings (yes I still have a house phone) when I am not there. They call from that umber up to 6 times a day.
I believe it is associated with NationStar Mortgage Company. I got a new job and updated my work contact with them and I started receiving the calls on my work phone. They do end up leaving a voicemail on my office phone, asking if I want to lower my mortgage rates.
They just called...two calls. The first time they hang up before my phone actually rang, then redialed. Didn't recognize the number so I didn't answer at all. No message.