Coincidence Numbers

★ 6/10Diophantine Equations number theory Casework

Problem

For a positive integer $n$ , let $s(n)$ be the sum and $p(n)$ the product of its digits. Call $n$ a coincidence number if

s(n) + p(n) = n.

Find the sum of all coincidence numbers.

Answer

Solution

Difficulty	6/10
Topics	Diophantine Equations, number theory, Casework

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