What is the largest multiple of this product which has distinct digits ?
(2) What is the maximum number of digits a square-free integer (whether even or odd) can have if its digits are all distinct?
(3) What is the largest odd square-free integer with distinct digits having exactly n prime factors for n = 1,2,3,4,5? You can extend this to larger numbers of factors if you wish.
Note: a square-free integer is one whose prime factorization has exactly one factor for each prime that appears in it.