8811
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 14040
- Proper Divisor Sum (Aliquot Sum)
- 5229
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5280
- Möbius Function
- 0
- Radical
- 2937
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 52
- 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
- no
- Odd
- yes
Appears in sequences
- Number of partitions in expanding space: sigma(n,q) is the sum of the q-th powers of the divisors of n.at n=6A023881
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (composite numbers), t = (primes).at n=23A024604
- "BHK" (reversible, identity, unlabeled) transform of 1,0,1,0...(odds).at n=21A032089
- Number of binary words of length n (beginning with 0) whose autocorrelation function is the indicator of a singleton.at n=15A045690
- a(n)=Sum{T(2i,n-2i): i=0,1,...,[ n/2 ]}, array T as in A049600.at n=11A049601
- Number of factorizations with 2 levels of parentheses indexed by prime signatures. A050338(A025487).at n=33A050339
- Number of (s(0), s(1), ..., s(n)) such that 0 < s(i) < 5 and |s(i) - s(i-1)| <= 1 for i = 1,2,...,n, s(0) = 2, s(n) = 4.at n=11A094292
- Iccanobirt numbers (13 of 15): a(n) = R(R(a(n-1)) + a(n-2) + R(a(n-3))), where R is the digit reversal function A004086.at n=14A102123
- a(n)/4^n is the measure of the subset of [0,1] remaining when all intervals of the form [b/2^m - 1/2^(2m+1), b/2^m + 1/2^(2m+1)] have been removed, with b and m positive integers, b<2^m and m<=n.at n=7A105284
- Numbers k such that k*(k+5) gives the concatenation of two numbers m and m+9.at n=1A116351
- Multiples of 11 containing an 11 in their decimal representation.at n=25A121031
- a(n) = n*(8*n+3).at n=33A139276
- Triangle T(n, k) = T(n-1, k-1) + 3*T(n-1, k) + 2*T(n-1, k-1), with T(n,1) = T(n, n) = 1, read by rows.at n=30A142596
- Triangle T(n, k) = T(n-1, k-1) + 3*T(n-1, k) + 2*T(n-1, k-1), with T(n,1) = T(n, n) = 1, read by rows.at n=33A142596
- Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a one by five or five by one block.at n=11A145965
- Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1100-1111-0100 pattern in any orientation.at n=10A146709
- Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1100-1111-0100 pattern in any orientation.at n=22A146711
- a(n) is the integer whose decimal representation consists of n 8's followed by n 1's.at n=2A184337
- Numbers consisting of ones and eights.at n=26A213084
- List of words over {1,8} with equal numbers of 1's and 8's.at n=7A214531