You want to carefully review the application materials. While some of the advice on this thread is true for some programs, it is not uniformly true for all programs. In other words, some departments explicitly state that they expect you to apply to work with one mentor, and if that is the case, I don't think it would be in your benefit, and it may actually work against you, to list any other faculty. However, other programs, for example, the program I was admitted to, actually want you to be a good fit for the program generally, so they expect you to be able to fit in with a number of faculty in the program. If you only pick one faculty member and don't speak generally on your fit with the department, then your application will be dinged (and I've seen applications immediately thrown out for this reason). I can think of two and possibly three other programs that ran this model. Much of the reason for this is that some departments pool faculty money (either intramural or extramural funding) to admit students and then faculty share doctoral students. For example, I split my time between two labs, one was the primary mentor I applied to work with, and the other was one of the other two faculty I explained had complementary interests to mine. And it shows even within cohorts - my entire cohort had overlapping interests and its clear why they selected us, both as a cohort, and in regards to the program in general.
So in sum, just read application materials very closely. While most likely the norm is for programs to not exactly be clear about whether they run a strict 1:1 mentor model, or whether they rather see your fit within the general department/program, many do explicitly state what they want.