Appealing Numbers
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Ivars Peterson (MathTrek)  
A short history of amicable numbers  pairs in which each number is the sum of the proper divisors of the other. The smallest such pair is 220 and 284. The number 220 is evenly divisible by 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, and 110, which add up to 284; and 284 is evenly divisible by 1, 2, 4, 71, and 142, which add up to 220. The Pythagorean brotherhood regarded 220 and 284 as numerical symbols of friendship.  


Levels:  High School (912), College 
Languages:  English 
Resource Types:  Articles 
Math Topics:  Number Sense/About Numbers, History and Biography, Sequences and Sets 
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