Talk to him, say hi. The way to stick out, is to be yourself and don't do what those airheads do! If he doesn't appreciate what you bring to the table, then find someone who's really worth you.

"Wow, that professor is really ______, huh? Hey, my name's _________, by the way. What's yours? Nice to meet you. So what's your major? What year are you? Where are you from? What do you want to do when you graduate? Would you maybe like to go get coffee together sometime or something?"

Ask a lot of questions, but also tell him about yourself. If you say something a little silly, maybe even slightly embarrassing, but still cute, you'll stick out. Being able to be a little vulnerable around a guy makes you stick out from other girls. But don't fake anything. Just... be yourself, and don't be afraid to make conversation. If it doesn't work out, it doesn't work out, and you can move on.

Maybe start by sitting next to him in class, then you can start talking about the class, what you think about it ect then move on to talking about other subjects you study, anything else you do at college, hobbies ect
And as for him not being interested in the sorority girls that are throwing themselves at him, he might not like that kind of girl, alot of guys prefer a girl who is themself, all the faking and high mantenence shit just turns them off
best of luck :)

the best way to not be seen as throwing yourself at him is to just be a friend to him first and see how it developes :)