EntityQ1164125· pop 13· linked from 229 articlessuperperfect numberSign in to savepositive integer which equals half of the sum of the divisors of the sum of its divisorsConnectionsprime numberEntityparityEntityOn-Line Encyclopedia of Integer SequencesEntitypower of twoEntityfigurate numberEntitysociable numberEntityautomorphic numberEntitymultiply perfect numberEntityInternational Standard Book NumberEntitynatural numberEntityintegerEntitynumber theoryEntity16Entitydigital object identifierEntitybinary numeral systemEntitydigitEntityexponentiationEntitynumeral systemEntity64Entitythree-dimensional spaceEntityCategoriesDivisor functionInteger sequencesUnsolved problems in number theory