  For a positive integer $n$, let $\sigma(n)$ denote the sum of the positive
divisors of $n$. Let $d$ be a proper divisor of $n$. We call $n$ a
deficient-perfect number if $\sigma(n)=2n-d$. In this paper, we show that the
only odd deficient-perfect number with four distinct prime divisors is
$3^{2}\cdot 7^{2}\cdot 11^{2}\cdot 13^{2}$.
