Been getting calls from this number periodically for a couple of months now, never leaving a message.  When you google the number you'll find it linked to a name on a site called "Hodges Directory".  This domain was registered to appear like a US company but is actually owned by a company called "European Web Invest" with no discernible web presence.  If you search for this company, it will turn up dead ends and forums that go into detail about previous, malicious actions taken by this "company".

I don't know if the number being listed there is a red flag or not, but the site itself certainly is.  There is no contact information on the site nor even a way to find out who owns the site without doing a domain lookup.  There is also placeholder text still sitting there despite the site being recently "updated" in 2016.

Again, not sure if the number and the website have any correlation with each other but it's worth noting nonetheless.