On the ratio of the sum of divisors and Euler's totient function. II.
J. Integer Seq. 17(9), Article 14.9.2, 22 p., electronic only (2014)
Summary
Summary: We find the form of all solutions to $\phi (n) | \sigma (n)$ with three or fewer prime factors, except when the quotient is 4 and $n$ is even.
