🌐EnglishEnglishDeutschEspañolFrançaisNederlandsРусскийالعربية中文日本語EntityQ1663510· pop 16· linked from 260 articlesaliquot sequencemathematical recursive sequenceAvailable in 16 languagesEspañolFrançaisDeutsch中文日本語РусскийالعربيةDanishHebrewHungarianConnectionsprime numberEntityperfect numberEntityCategoriesArithmetic dynamicsArithmetic functionsDivisor function