I can't tell you the exact specifications but it's quite beefy and generally takes several hours to download so be prepared for that.
You should also note that, before buying it, the university should provide it to you for free, so wait until term starts and make sure they aren't offering it on a student license at your uni.
EDIT: According to the Mathworks website, you need a recent OS (windows 7 upwards for the 2016 versions), any Intel or AMD processor, 4-6GB disk space and 2GB RAM