Printer Friendly
Dictionary, Encyclopedia and Thesaurus - The Free Dictionary
3,895,931,644 visitors served.
forum Join the Word of the Day Mailing List For webmasters
?
Dictionary/
thesaurus
Medical
dictionary
Legal
dictionary
Financial
dictionary
Acronyms
 
Idioms
Encyclopedia
Wikipedia
encyclopedia
?

Amicable Numbers

   Also found in: Dictionary/thesaurus, Wikipedia 0.01 sec.
amicable numbers [′am·ə·kə·bəl ′nəm·bərz]
(mathematics)
Two numbers such that the exact divisors of each number (except the number itself) add up to the other number.

Amicable Numbers 

a pair of natural numbers, each of which is equal to the sum of all the exact divisors of the other, that is, divisors that are different from the number itself. The amicable numbers 284 and 220, whose corresponding sums of divisors are 1 + 2 + 4 + 5 + 10 + 11 + 20 + 22 + 44 + 55 + 110 = 284 and 1 + 2 + 4 + 71 + 142 = 220, were already known in antiquity. Assigning a mystical meaning to the properties of numbers, the Pythagoreans attached great importance to amicable numbers. L. Euler found approximately 60 pairs of amicable numbers. The use of computers has made it possible to find several hundred more pairs of amicable numbers. These numbers are primarily of historical interest.



Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content.
?Page tools
Printer friendly
Cite / link
Feedback
Mentioned in?  References in periodicals archive?   Encyclopedia browser?   Full browser?
No references found
 
Well-represented here are Euler's contributions to geometry, including his enhancements of Pythagoras, number theory, including his work on odd perfect numbers and amicable numbers, combinatorics, including his work on Venn diagrams and orthogonal matrices, and a full range of his work in analysis, one article of which shows how Euler discovered America.
 
 
 
Encyclopedia
?

Terms of Use | Privacy policy | Feedback | Advertise with Us | Copyright © 2012 Farlex, Inc.
Disclaimer
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.