{"title":"图腾的一些特性","authors":"Pentti Haukkanen","doi":"10.1007/s11139-024-00921-7","DOIUrl":null,"url":null,"abstract":"<p>A arithmetical function <i>f</i> is said to be a totient if there exist completely multiplicative functions <span>\\(f_t\\)</span> and <span>\\(f_v\\)</span> such that<span>\\( f=f_t*f_v^{-1}, \\)</span> where <span>\\(*\\)</span> is the Dirichlet convolution. Euler’s <span>\\(\\phi \\)</span>-function is an important example of a totient. In this paper we find the structure of the usual product of two totients, the usual integer power of totients, the usual product of a totient and a specially multiplicative function and the usual product of a totient and a completely multiplicative function. These results are derived with the aid of generating series. We also provide some distributive-like characterizations of totients involving the usual product and the Dirichlet convolution of arithmetical functions. They give as corollaries characterizations of completely multiplicative functions.</p>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"144 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Some properties of totients\",\"authors\":\"Pentti Haukkanen\",\"doi\":\"10.1007/s11139-024-00921-7\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>A arithmetical function <i>f</i> is said to be a totient if there exist completely multiplicative functions <span>\\\\(f_t\\\\)</span> and <span>\\\\(f_v\\\\)</span> such that<span>\\\\( f=f_t*f_v^{-1}, \\\\)</span> where <span>\\\\(*\\\\)</span> is the Dirichlet convolution. Euler’s <span>\\\\(\\\\phi \\\\)</span>-function is an important example of a totient. In this paper we find the structure of the usual product of two totients, the usual integer power of totients, the usual product of a totient and a specially multiplicative function and the usual product of a totient and a completely multiplicative function. These results are derived with the aid of generating series. We also provide some distributive-like characterizations of totients involving the usual product and the Dirichlet convolution of arithmetical functions. They give as corollaries characterizations of completely multiplicative functions.</p>\",\"PeriodicalId\":501430,\"journal\":{\"name\":\"The Ramanujan Journal\",\"volume\":\"144 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"The Ramanujan Journal\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1007/s11139-024-00921-7\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Ramanujan Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1007/s11139-024-00921-7","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
A arithmetical function f is said to be a totient if there exist completely multiplicative functions \(f_t\) and \(f_v\) such that\( f=f_t*f_v^{-1}, \) where \(*\) is the Dirichlet convolution. Euler’s \(\phi \)-function is an important example of a totient. In this paper we find the structure of the usual product of two totients, the usual integer power of totients, the usual product of a totient and a specially multiplicative function and the usual product of a totient and a completely multiplicative function. These results are derived with the aid of generating series. We also provide some distributive-like characterizations of totients involving the usual product and the Dirichlet convolution of arithmetical functions. They give as corollaries characterizations of completely multiplicative functions.