Manuals/calci/PERFECTNUMBERS

PERFECTNUMBERS (Upto,StartFrom)

Description

This function returns the list of Perfect numbers.
In PERFECTNUMBERS (Upto,StartFrom),Upto is the Maximum number limit to display and Start from is the Minimum number to start Perfect number list.
Perfect number is a positive integer which is equal to the sum of its proper divisors.
The smallest perfect number is 6, which is the sum of 1, 2, and 3.

Abundant number is a number for which the sum of its proper divisors is greater than the number itself.
It is also called Excessive Number.
The first Abundant number is 12.
Its proper divisors are 1, 2, 3, 4 and 6 for a total of 16.
The amount by which the sum exceeds the number is the abundance. The number 12 has an abundance of 4.
ABUNDANTNUMBERS(110) = 12 18 20 24 30 36 40 42 48 54 56 60 66 70 72 78 80 84 88 90 96 100 102 104 108

Deficient number is a number $n$ for which the sum of divisors $\sigma (n)<2n$ , or, equivalently, the sum of proper divisors (or aliquot sum) $s(n)<n$ . The value Failed to parse (syntax error): {\displaystyle 2n − \sigma(n)} (or Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle n − s(n)} ) is called the number's deficiency.