Amazon delivery. It's a generic number from Amazon that is used instead of the actual driver / delivery person who is trying to contact you. Chances are the delivery person forgot something or needs an access code, etc. If you call back - it's just Amz customer service.
It was my Amazon Prime Now delivery driver. I'm in Dallas btw so of course it's a non local number that made me suspicious. Glad to know now that I should answer and will save for future reference since I order from them constantly.
Got a call from this number and they hung up immediately upon answering. Seconds later, I got a call from the Amazon delivery call center with a phone number of 877 252-2701 telling me that my amazon delivery driver was outside of my residence and he didn't want to leave a package outdoors.