We derive new formulas for the number of unordered (distinct) factorizations with
k parts of a positive integer
n as sums over the partitions of
k and an auxiliary function, the number of partitions of the prime exponents of
n, where the parts have a specific number of colors. As a consequence, some new relations between partitions, Bell numbers and Stirling number of the second kind are
... [Show full abstract] derived. We also derive a recursive formula for the number of unordered factorizations with k different parts and a simple recursive formula for the number of partitions with k different parts.