  A positive integer $n$ is practical if every $m \leq n$ can be written as a
sum of distinct divisors of $n$. One can generalize the concept of practical
numbers by applying an arithmetic function $f$ to each of the divisors of $n$
and asking whether all integers in a given interval can be expressed as sums of
$f(d)$'s, where the $d$'s are distinct divisors of $n$. We will refer to such
$n$ as `$f$-practical.' In this paper, we introduce the $f$-practical numbers
for the first time. We give criteria for when all $f$-practical numbers can be
constructed via a simple necessary-and-sufficient condition, demonstrate that
it is possible to construct $f$-practical sets with any asymptotic density, and
prove a series of results related to the distribution of $f$-practical numbers
for many well-known arithmetic functions $f$.
