1.2 KiB

Raw Blame History

id	title	challengeType	forumTopicId	dashedName
5900f3b21000cf542c50fec5	Problem 70: Totient permutation	5	302183	problem-70-totient-permutation

--description--

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.

--hints--

totientPermutation() should return a number.

assert(typeof totientPermutation() === 'number');

totientPermutation() should return 8319823.

assert.strictEqual(totientPermutation(), 8319823);

--seed--

--seed-contents--

function totientPermutation() {

  return true;
}

totientPermutation();

--solutions--

// solution required

1.2 KiB Raw Blame History