Story of Totient Function

Euler’s totient function counts the number of positive integers up to a given integer N that are relatively prime to N. Formally, it is the count of integers K in range 1 ≤ K ≤ N for which the greatest common divisor gcd(N, K) equal to 1. It is denoted as ϕ(N).


This is a companion discussion topic for the original entry at https://toph.co/p/story-of-totient-function