Friendly number

Rarity: Common

The most frequent rarity: most Wikipedia articles become Commons.

Rarity follows how well known the article is: its views on the French and English Wikipedia over a year, and the number of languages it exists in.

At a glance

Class

Notion

Domain

Science and technology

In collections

Nobody has pulled it yet.

What Wikipedia says

In number theory, friendly numbers are two or more natural numbers with a common abundancy index, the ratio between the sum of divisors of a number and the number itself. Two numbers with the same "abundancy" form a friendly pair; n numbers with the same abundancy form a friendly n-tuple.

Excerpt from the Wikipedia article “Friendly number”, under the CC BY-SA 4.0 license. Read the article on Wikipedia