Thanks every one, Hi_nanu, Regarding the mathematical menaing of AMICABLE, I think they characterized the two numbers as being friends to each other. In math, it is called a relation and depends how you define. So, here in your example, the define the friendship between any two numbers in the described way. BTW, its again my turn to throw new word: EMULOUS: (Adjectives): Arising from emulation or imitation/ Eager to surpass others.