Abstract:In this paper, we study relations between free probability on crossed product W * -algebras with a von Neumann algebra over p-adic number fields Q p (for primes p), and free probability on the subalgebra Φ, generated by the Euler totient function φ, of the arithmetic algebra A, consisting of all arithmetic functions. In particular, we apply such free probability to consider operator-theoretic and operator-algebraic properties of W * -dynamical systems induced by Q p under free-probabilistic (and hence, spectral-theoretic) techniques.