I got a call from the same number (636 261 9319) on my cell phone. I did not answer the call because i did not recognize the # and they did not leave any message.
This is an automated dialer for CitiMortgage - I finally answered it and talked to an account service rep about my existing mortgage - she was able to identify herself as a valid Citi representative. Doesn't appear to be a phone scam, but just an annoying way to contact their account holders.