4312440

Appears in sequences

• Numbers n such that (phi(n) + sigma(n))/(rad(n))^2 is an integer > 1 (phi=A000010, sigma=A000203, rad=A007947).at n=21A097982
• Numbers k such that (phi(k) + sigma(k))/rad(k)^2 is an integer, that is (phi(k) + sigma(k)) is divisible by every prime factor of k squared.at n=23A121850
• Sequence lists numbers k > 1 such that k^4 == phi(k) (mod sigma(k)), where phi = A000010 and sigma = A000203.at n=20A324216
• Abundant numbers k such that k^2 + A033880(k)^2 is a perfect square.at n=16A377134