43657

Appears in sequences

• Smallest number that requires n iterations of the unitary totient function (A047994) to reach 1.at n=26A003271
• (n - phi(n)) | sigma(n) for composite n not congruent to 2 (mod 4).at n=37A055164
• a(n) is the least k, not multiple of 10, such that k^k contains a palindromic substring of length n.at n=19A115943
• Numbers n such that T(n) + T(n+1) + ... + T(n+24) is a square, where T = A000217 (triangular numbers).at n=8A257708
• Numbers m such that psi(x) = phi(m) has a solution while sigma(y) = phi(m) has none.at n=38A291524