University of Colorado, Boulder
Our number theory seminar is Tuesdays at 11 am in Math 350 for Spring 2017. You can view the schedule here by clicking on "number theory".
You should fly in to Denver International Airport (DEN), which is a United hub but also serves pretty much all the other airlines. The airport is generally fairly efficient, so when flying out, if you have no checked bags, an hour at the airport is often sufficient, but I'll still recommend 1.5 hrs to be safe.
My personal preference is the city bus for efficiency, but you are more than welcome to use a shuttle service, which will drop you directly at your hotel.
City Bus: RTD's route "AB Boulder/DIA", which is comfortable, fast, frequent, and pretty reliably on schedule. It costs $9 (exact change; ask for a receipt), and you can find it by going out the main door in the south side of the building (same direction as the giant Westin hotel, marked with a huge American Flag), then down the long escalator.
Shuttle: In order to get drop off and pick up at your hotel, you are equally welcome to use a shuttle. I prefer GreenRide to SuperShuttle based on personal experience. You can reserve ahead, just ask at the airport, or we can arrange and pay for it for you ahead of time (just ask).
The department will reserve and prepay your hotel for you at the Best Western Plus Inn Boulder on 28th St (don't get confused, there's another Best Western in Boulder). The Best Western is a 15 minute walk from the mathematics department (google recognises "mathematics building" which is at the corner of Colorado and Folsom). It is a five minutes walk from grocery and restaurants.