Wang, Shaoheng; Liu, Shuiqiang Perfect numbers and pseudoperfect numbers. (Chinese. English summary) Zbl 0984.11004 Acta Sci. Nat. Univ. Norm. Hunanensis 23, No. 2, 33-36 (2000). A number is called pseudoperfect if it is the sum of some of its divisors, and primitive pseudoperfect if it is pseudoperfect but none of its proper divisors are. The authors study such numbers having the forms \(p^t\), \(pq\), \(pqr\), \(pqrs\), \(2^t p\), \(p^tq\), where \(p, q, r, s\) are primes. Reviewer: Peter Shiu (Loughborough) MSC: 11A25 Arithmetic functions; related numbers; inversion formulas PDFBibTeX XMLCite \textit{S. Wang} and \textit{S. Liu}, Acta Sci. Nat. Univ. Norm. Hunanensis 23, No. 2, 33--36 (2000; Zbl 0984.11004)