🌐EnglishEnglishBahasa IndonesiaEspañolFrançaisNederlandsPolskiTiếng Việt한국어中文EntityQ22912133· pop 13· linked from 53 articlesaliquot sumsum of all proper divisors of a natural numberConnectionsnatural numberEntityprime numberEntityCategoriesArithmetic dynamicsArithmetic functionsDivisor functionPerfect numbers