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Viewing Version 3 of 'proper divisor'
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Title of object: proper divisor
Canonical Name: ProperDivisor
Type: Definition

Created on: 2006-04-23 15:44:07
Modified on: 2006-04-23 16:24:08

Creator: CompositeFan
Modifier: CompositeFan
Author: CompositeFan

Classification: msc:11A51
Synonyms: proper divisor=aliquot part

Revision comment (for changes between this and next version):

Clearer about positive divisors (I hope); restricted divisor; examples

Preamble:

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Content:

If a divisor $d$ of $n$ (that is, $d|n$) satisfies $0 < d < n$, then $d$ is a {\em proper divisor} of $n$.

By restricting the sum of divisors to proper divisors, some $n$ will be less than this sum (deficient numbers, including prime numbers), some will be equal (perfect numbers) and some will be greater (abundant numbers).