I will need to do a proper count when I get home, but I have enough to go about two weeks before needing to do laundry. But really that assumes that I have been working for those two weeks. I have about two weeks worth of acceptable work clothing (all long sleeves and mostly sweaters because it's flippin freezing in my office, no matter the time of year).
As for other types of shirts, mostly T-shirts, I have lots of those but don't wear most of them, since I only use them on weekends now. I used to dress in such shirts every day. I could probably get rid of many of them now.