--- id: 5900f3b11000cf542c50fec4 title: 'Problem 69: Totient maximum' challengeType: 5 forumTopicId: 302181 dashedName: problem-69-totient-maximum --- # --description-- Euler's Totient function, φ(`n`) \[sometimes called the phi function], is used to determine the number of numbers less than `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.
| !!crwdBlockTags_15_sgaTkcolBdwrc!! | Relatively Prime | φ(!!crwdBlockTags_16_sgaTkcolBdwrc!!) |!!crwdBlockTags_17_sgaTkcolBdwrc!!/φ(!!crwdBlockTags_18_sgaTkcolBdwrc!!) | | ------------ | ---------------- | --------------- | ---------------------------- | | 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 `n`/φ(`n`) for `n` ≤ 10. Find the value of `n` ≤ 1,000,000 for which n/φ(`n`) is a maximum. # --hints-- `totientMaximum()` should return a number. ```js assert(typeof totientMaximum() === 'number'); ``` `totientMaximum()` should return 510510. ```js assert.strictEqual(totientMaximum(), 510510); ``` # --seed-- ## --seed-contents-- ```js function totientMaximum() { return true; } totientMaximum(); ``` # --solutions-- ```js // solution required ```