181427

Appears in sequences

• Composite numbers n such that sigma(n+24) = sigma(n) + 24.at n=31A054983
• Numbers k such that (k, k+2) are not twin primes yet sigma(k+2)/d(k+2) - sigma(k)/d(k) = 1.at n=5A322668
• Numbers k such that k and k+2 have the same deficiency (A033879).at n=5A330901
• Odd numbers k such that phi(k) = phi(k+2), where phi is the Euler totient function (A000010).at n=16A333741
• Numbers k such that k and k+2 have the same unitary abundance (A129468).at n=21A335252