43861478400
domain: N
Appears in sequences
- Multiply-perfect numbers: n divides sigma(n).at n=21A007691
- 4-perfect (quadruply-perfect or sous-triple) numbers: sum of divisors of n is 4n.at n=7A027687
- Multiply perfect numbers that are also harmonic numbers but are not arithmetic numbers.at n=9A046986
- Numbers k whose average divisor is nonintegral and divides k.at n=21A046999
- Numbers m such that m = sigma(abs(k)) - 3k, where k = sigma(m) - 3m.at n=15A069146
- Multiply perfect numbers k for which the quotient sigma_3(k)/k = A001158(k)/k is nonintegral.at n=5A088844
- Multiply perfect numbers k such that sigma(k)/k > 2.at n=14A166069
- Trajectory of 2 under the map x -> A274940(x).at n=29A274941
- Nonprime numbers k such that k | (sigma(k) - Sum_{j=1..m}{sigma(k) mod d_j}), where d_j is one of the m divisors of k.at n=26A282775
- Multi-perfect numbers m from A007691 such that m*(m-tau(m))/sigma(m) is an integer h, where k-tau(k) is the number of nondivisors of k (A049820) and sigma(k) is the sum of the divisors of k (A000203).at n=16A325023
- Numbers that are multi-perfect (A007691) and simultaneously harmonic (A001599).at n=17A325025
- Numbers k for which gcd(2k, sigma(k)) = 2k.at n=13A325637
- Multiply-perfect numbers m whose average divisor is not an integer.at n=13A330533
- Numbers whose abundancy index is a power of 2.at n=14A336702
- Numbers k such that both sigma_{-1}(k) > 2 and sigma_0(k)/sigma_{-1}(k) are integers.at n=10A340864
- Multiply-perfect numbers k that do not have a divisor d such that sigma(d)*d = k.at n=6A348032
- Multiply-perfect numbers that are the sum of the divisors of some number.at n=20A354073
- Multiperfect numbers k for which gcd(k,A003961(k))*gcd(sigma(k),A276086(k)) is equal to gcd(k,A276086(k))*gcd(sigma(k),A003961(k)), where A003961(n) is fully multiplicative with a(prime(i)) = prime(i+1), and A276086 is the primorial base exp-function.at n=15A379491