Vipul: Created page with '{{natural number property}} ==Definition== A natural number $n$ is termed a '''deficient number''' if $\sigma(n) < 2n$ , where $\sigma$ deno...'

2009-03-21T23:44:24Z

Created page with '{{natural number property}} ==Definition== A natural number <math>n</math> is termed a '''deficient number''' if <math>\sigma(n) < 2n</math>, where <math>\sigma</math> deno...'

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{{natural number property}}

==Definition==

A [[natural number]] <math>n</math> is termed a '''deficient number''' if <math>\sigma(n) < 2n</math>, where <math>\sigma</math> denotes the [[defining ingredient::divisor sum function]]. In other words, <math>n</math> is greater than the sum of all its proper positive divisors.

==Relation with other properties==

===Opposite properties===

* [[Perfect number]]: This requires <math>\sigma(n) = 2n</math>.
* [[Abundant number]]: This requires <math>\sigma(n) > 2n</math>.

===Stronger properties===

* [[Weaker than::Almost perfect number]]: A natural number <math>n</math> such that <math>\sigma(n) = 2n - 1</math>.

Deficient number - Revision history

Vipul: Created page with '{{natural number property}} ==Definition== A natural number n is termed a '''deficient number''' if \sigma(n) < 2n, where \sigma deno...'

Vipul: Created page with '{{natural number property}} ==Definition== A natural number $n$ is termed a '''deficient number''' if $\sigma(n) < 2n$ , where $\sigma$ deno...'