different prime factors

The distinct prime factors of a positive integer n>=2 are defined as the ω(n) numbers p_1, ..., p_(ω(n)) in the prime factorization n = p_1^(a_1) p_2^(a_2) ...p_(ω(n))^(a_(ω(n))) (Hardy and Wright 1979, p. 354). A list of distinct prime factors of a number n can be computed in the Wolfram Language using FactorInteger[n][[All, 1]], and the number ω(n) of distinct prime factors is implemented as PrimeNu[n].

Dedekind function | distinct prime factorization | divisor function | Erdős-Kac theorem | greatest prime factor | Hardy-Ramanujan theorem | heterogeneous numbers | least prime factor | Mertens constant | prime factor | squarefree