What is a Lonely Number? What is a Friendly Number? What are these friends you speak of?

Question

anonymous · Answer

What is this question meant for my brother @psujono

anonymous · Answer

lol, 1 is Lonely number. :D

anonymous · Answer

Or, must be.

anonymous · Answer

Check it out here
mathworld.wolfram.com/FriendlyNumber.html

I don't get it. Seems very odd

anonymous · Answer

Friendly numbers are the numbers with same  abundancy.

anonymous · Answer

Golden Globe Nominated :D

anonymous · Answer

^ sorry, not lonely numbers, solitary numbers

anonymous · Answer

@FoolForMath is well versed in this topic! and @Ishaan94 is as well so let them answer!

anonymous · Answer

The abundancy of n is the rational number $ σ(n) / n $, in which σ denotes the sum of divisors function. A number n is a friendly number if there exists m ≠ n such that σ(m) / m = σ(n) / n. Note that abundancy is not the same as abundance which is defined as σ(n) − 2n.

From Wikipedia.

anonymous · Answer

So why aren't we sure if 10 is solitary? http://www.mathsisgoodforyou.com/conjecturestheorems/10solitary.htm

anonymous · Answer

because friends are rare, and we all are basically alone (solitary)