Published online by Cambridge University Press: 23 May 2014
For a positive integer $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}n$, 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 there are no odd deficient-perfect numbers with three distinct prime divisors.