Totient maximum
Euler's Totient function, \( \phi(n) \) [sometimes called the phi function], is defined as the number of positive integers not exceeding n which are relatively prime to n. For example, as \( 1 \), \( 2 \), \( 4 \), \( 5 \), \( 7 \), and \( 8 \), are all less than or equal to nine and relatively prime to nine, \( \phi(9)=6 \).
$n$ Relatively Prime $\phi(n)$ $n/\phi(n)$ 2 1 1 2 3 1,2 2 1.5 4 1,3 2 2 5 1,2,3,4 4 1.25 6 1,5 2 3 7 1,2,3,4,5,6 6 1.1666... 8 1,3,5,7 4 2 9 1,2,4,5,7,8 6 1.5 10 1,3,7,9 4 2.5 It can be seen that \( n=6 \) produces a maximum \( \frac{n}{\phi(n)} \) for \( n\leq 10 \).
Find the value of \( n\leq 1,000,000 \) for which \( \frac{n}{\phi(n)} \) is a maximum.