# Problem 70: Totient permutation

![graphic](img070.gif)

Euler's Totient function, φ(n) \[sometimes called the phi function\], is
used to determine the number of positive numbers less than or equal to n
which are relatively prime to n. For example, as 1, 2, 4, 5, 7, and 8,
are all less than nine and relatively prime to nine, φ(9)=6.The number 1
is considered to be relatively prime to every positive number, so
φ(1)=1. Interestingly, φ(87109)=79180, and it can be seen that 87109 is
a permutation of 79180. Find the value of n, 1 < n < 107, for
which φ(n) is a permutation of n and the ratio n/φ(n) produces a
minimum.