  The Zero divisor Graph of a commutative ring $R$, denoted by $\Gamma[R]$, is
a graph whose vertices are non-zero zero divisors of R and two vertices are
adjacent if their product is zero. The compressed zero divisor graph
$\Gamma_E[R]$ is the (undirected) graph whose vertices are the equivalence
classes such that distinct vertices [r] and [s] are adjacent if and only if rs
= 0. In this paper we derive the characteristic polynomial and Wiener index of
the Compressed zero divisor graph $\Gamma_{E}[\mathbb{Z}_m]$ where $m=p^n$ with
prime $p$.
