This is a number from the University of Reno. It is to support their phonathon. It's not a scam or hackers, just the Wolf Call Center looking for support. You can find more info here.

https://www.unr.edu/giving/contact-us/wolf-call

So you pre-emptively posted that information, thinking people are not going to complain about getting unwanted calls from this number? Your post looks like spam, promoting the organization.

And if scammers start spoofing the number, no one will be able to trust calls from that number.

If it is UNR why do they hang up when the call is answered?

They don't  leave a  message.  Is there a way to be removed from the call list?