1307124000

Appears in sequences

• Numbers k such that gcd(sigma(k),k) = k/5.at n=33A067237
• Numbers k for which sigma(k)/k - 4/5 is an integer.at n=7A218427
• Harmonic numbers m from A001599 such that m*(m-tau(m))/sigma(m) is an integer h, where k-tau(k) is the number of nondivisors of k (A049820), tau(k) is the number of divisors of k (A000005), and sigma(k) is the sum of the divisors of k (A000203).at n=28A325021
• Harmonic numbers (A001599) with a record number of divisors.at n=20A335317
• Harmonic numbers k with a record number of primes p not dividing k such that k*p is also a harmonic number.at n=8A335368
• Harmonic numbers (A001599) with a record number of divisors that are harmonic numbers.at n=11A335388
• Numbers k that have a record number of common divisors with sigma(k).at n=19A378267