# Wikipedia Authors - Euler's Totient Function (Highlights) ![rw-book-cover|256](https://upload.wikimedia.org/wikipedia/commons/thumb/9/9b/EulerPhi.svg/1200px-EulerPhi.svg.png) ## Metadata **Review**:: [readwise.io](https://readwise.io/bookreview/38418771) **Source**:: #from/readwise #from/reader **Zettel**:: #zettel/fleeting **Status**:: #x **Authors**:: [[Wikipedia Authors]] **Full Title**:: Euler's Totient Function **Category**:: #articles #readwise/articles **Category Icon**:: 📰 **URL**:: [en.wikipedia.org](https://en.wikipedia.org/wiki/Euler%27s_totient_function) **Host**:: [[en.wikipedia.org]] **Highlighted**:: [[2024-03-06]] **Created**:: [[2024-03-06]] ## Highlights - **Euler's totient function** counts the positive integers up to a given integer n that are relatively prime to n. It is written using the Greek letter *phi* as $\varphi (n)$ or $\phi(n)$, and may also be called **Euler's phi function**. In other words, it is the number of integers k in the range 1 ≤ _k_ ≤ _n_ for which the greatest common divisor gcd(_n_, _k_) is equal to 1. ([View Highlight](https://read.readwise.io/read/01hr9mp445zaqd6903jd99yz7d)) ^688822912