189728

Appears in sequences

• Numbers k such that the harmonic mean of the divisors of k is the square of a rational number.at n=25A074266
• a(n) = n*(n+1)*(n+7)*(122+57*n+n^2)/120.at n=20A101862
• Numbers with prime factorization p^2*q^2*r^5 where p, q, and r are distinct primes.at n=15A190114
• Numbers k such that both k and sigma(k)=A000203(k) are powerful, i.e., are terms of A001694.at n=8A337044
• Indecomposable sigma-powerful numbers: powerful numbers k such that sigma(k) is also powerful, but restricted to terms that are not the product of 2 terms > 1 of A337044.at n=4A337045
• Powerful numbers (A001694) whose sum of powerful divisors (including 1) is also powerful.at n=12A349109