8840
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 22680
- Proper Divisor Sum (Aliquot Sum)
- 13840
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3072
- Möbius Function
- 0
- Radical
- 2210
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 4
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 96
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- a(n) = floor(n(n+2)(2n+1)/8).at n=32A002717
- Define predecessors of n, P(n), to consist of numbers whose binary representation is obtained from that of n by replacing 10 with 01 or changing a final 1 to a 0; then a(0)=1, a(n) = Sum a(P(n)), n>0.at n=55A004065
- Expansion of e.g.f. sinh(log(1+tan(x))).at n=7A009569
- Expansion of x/(1 - 5*x - 9*x^2).at n=6A015545
- a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t is A000201 (lower Wythoff sequence).at n=38A023866
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 47.at n=18A031545
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 47.at n=1A031725
- Numbers in which 0,1,2,3,4,5 all occur in base 6.at n=17A031947
- Every run of digits of n in base 16 has length 2.at n=37A033014
- Bisection of A028289.at n=47A038390
- Positive integers having more base-16 runs of even length than odd.at n=39A044842
- Numbers whose base-4 representation contains exactly three 0's and four 2's.at n=8A045056
- Numbers k such that the sum of the squares of the divisors of k is divisible by k.at n=23A046762
- Digitally balanced numbers in base 6: equal numbers of 0's, 1's, ..., 5's.at n=17A049357
- Numbers k such that k | sigma_6(k).at n=32A055710
- Numbers n such that n | sigma_10(n).at n=46A055714
- a(n) = n^3 - n^2 + n - 1 = (n-1) * (n^2 + 1).at n=21A062158
- Numbers m such that DivisorSigma(4*k-2, m) mod m = 0 holds presumably for all k; that is, (4k-2)-power-sums of divisors of m are divisible by m for all k.at n=11A066290
- Even elements of A082931.at n=36A082933
- Least common multiple of prime(n+1)-1 and prime(n)-1.at n=31A083554