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problem 70 · 5 lines

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<p>Euler's totient function, $\phi(n)$ [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, $\phi(9)=6$.<br/>The number $1$ is considered to be relatively prime to every positive number, so $\phi(1)=1$. </p>
<p>Interestingly, $\phi(87109)=79180$, and it can be seen that $87109$ is a permutation of $79180$.</p>
<p>Find the value of $n$, $1 \lt n \lt 10^7$, for which $\phi(n)$ is a permutation of $n$ and the ratio $n/\phi(n)$ produces a minimum.</p>
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