Who called from 6232235973

Received a call from this number on October 15, 2015.  I did not answer, they did not leave a message.

Received a call from this number on October 30, 2015.  I did not answer, they did not leave a message.

I have received six missed calls from this number since June 2016. They never leave a message. I tried calling back and there is a voicemail just stating the phone number and to leave a message. This MAY be a realty company, I am in the process of buying a house.