In my hurricane emergency kit, I have a Radio Shack AM/FM radio about the same size as yours but it has an analog tuner.
It's quite heavy for the size and when I first got it, I checked out the reception and it's pretty good for the size of the radio and I see it's about half the price of the one you have, so yours may be even better.
If you ever get a real strong interest in daytime AM DXing and have the money to spend, you may want to look into getting a loop antenna to supplement your receiver.
This is the one I use for daytime DXing that I supplement to my Sangean PR-D5 radio.
http://www.amazon.com/Terk-Indoor-AM-Antenna-ADVANTAGE/dp/B000069EUW
On stations that are very weak, you notice a big difference and it can even get stations that you can't hear on the other radio at all. No connection is needed.
The thing is, it doesn't make much of a difference for nighttime AM reception, though some say it does. I haven't noticed a difference myself.
If you decide to make DXing a serious hobby, you may want to just upgrade to a bigger receiver if you can afford to. The people here can give you great suggestions.
Since you're new to DXing, you want to fully understand the difference between day and night reception and why night is so much better. Personally, I like daytime DXing as much as nighttime, if not more, because daytime signals are limited in their coverage and it's interesting to see how such distances can greatly exceed the norm where the land has good conductivity (like where you are) or especially if there's saltwater between your receiver and the stations (as is the case of the beaches here in Florida).
But again, if you have the time to search for certain stations, you'll be surprised how, in your location, you can hear starions in the middle of the day from hundreds of miles away, distances that are more associated with
nighttime AM reception.