{ "id": "2406.04018", "version": "v1", "published": "2024-06-06T12:44:03.000Z", "updated": "2024-06-06T12:44:03.000Z", "title": "Inequalities involving the primorial counting function", "authors": [ "Christian Axler" ], "categories": [ "math.NT" ], "abstract": "Let $\\varphi(n)$ denote the Euler totient function. In this paper, we first establish a new upper bound for $n/\\varphi(n)$ involving $K(n)$, the function that counts the number of primorials not exceeding $n$. In particular, this leads to an answer to a question raised by Aoudjit, Berkane, and Dusart concerning an upper bound for the sum-of-divisors function $\\sigma(n)$. Furthermore, we give some lower bounds for $N_k/\\varphi(N_k)$ as well as for $\\sigma(N_k)/N_k$, where $N_k$ denotes the $k$th primorial.", "revisions": [ { "version": "v1", "updated": "2024-06-06T12:44:03.000Z" } ], "analyses": { "keywords": [ "primorial counting function", "inequalities", "upper bound", "euler totient function", "th primorial" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }