Yamada, Tomohiro On the divisibility of odd perfect numbers, quasiperfect numbers and amicable numbers by a high power of a prime. (English) Zbl 1471.11014 Integers 20, Paper A91, 17 p. (2020). Reviewer: Juan Tena Ayuso (Valladolid) MSC: 11A25 11N35 11A41 11B25 PDFBibTeX XMLCite \textit{T. Yamada}, Integers 20, Paper A91, 17 p. (2020; Zbl 1471.11014) Full Text: arXiv Link
Yamada, Tomohiro An analog of perfect numbers involving the unitary totient function. (English) Zbl 1464.11003 J. Number Theory 209, 246-266 (2020). Reviewer: Pentti Haukkanen (Tampere) MSC: 11A05 11A25 11A51 11N36 PDFBibTeX XMLCite \textit{T. Yamada}, J. Number Theory 209, 246--266 (2020; Zbl 1464.11003) Full Text: DOI arXiv
Yamada, Tomohiro Quasiperfect numbers with the same exponent. (English) Zbl 1465.11041 Integers 19, Paper A35, 11 p. (2019). MSC: 11A25 11Y05 PDFBibTeX XMLCite \textit{T. Yamada}, Integers 19, Paper A35, 11 p. (2019; Zbl 1465.11041) Full Text: arXiv Link