2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/107610We study the function $Θ(x,y,z)$ that counts the number of positive integers $n\le x$ which have a divisor $d>z$ with the property that $p\le y$ for every prime $p$ dividing $d$. We also indicate some cryptographic applications of our results.Number Theory11N25, 94A60text