11952
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 30
- Divisor Sum
- 33852
- Proper Divisor Sum (Aliquot Sum)
- 21900
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3936
- Möbius Function
- 0
- Radical
- 498
- Omega Function (Ω)
- 7
- 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
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 50
- 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) = (d(n)-r(n))/2, where d = A026037 and r is the periodic sequence with fundamental period (1,0,0,1).at n=39A026038
- Theta series of 8-dimensional strongly 6-modular lattice O(6) with minimal norm 3.at n=31A029720
- Sorted elements of table (A035002) of a(m,n) = sum(a(m-k,n), k=1..m-1)+sum(a(m,n-k), k=1..n-1).at n=39A035001
- For n weights, number of combinations when limited to two weights per pan.at n=18A037255
- Triangle formed when the cumulative boustrophedon transform is applied to 1, 1, 1, 1, ..., read by rows from left to right.at n=23A059433
- Triangle formed when cumulative boustrophedon transform is applied to 1, 1, 1, 1, ..., read by rows in natural order.at n=25A059434
- Numbers k such that 3*2^k - 7 is prime.at n=32A059747
- a(n) = Product_{i=1..n} sigma(i) * Sum_{i=1..n} 1/sigma(i).at n=5A067577
- Centered 17-gonal numbers: (17*n^2 - 17*n + 2)/2.at n=37A069130
- Trajectory of 77 under the Reverse and Add! operation carried out in base 2.at n=11A075253
- Numbers k such that 2^k - 1 is divisible by (k-1).at n=19A087965
- a(n) = sigma_3(n) - sigma_1(n).at n=21A092348
- Numbers n such that A112131(n) is a Harshad number and sets a new record for number of digits.at n=9A109463
- Number of n-move paths on a 3 X 3 chessboard of a queen starting or ending in the central square.at n=5A180031
- Let S denote the palindromes in the language {0,1,2,...,n-1}*; a(n) = number of words of length 4 in the language SS.at n=17A187277
- Triangle of coefficients of polynomials v(n,x) jointly generated with A209767; see the Formula section.at n=49A209768
- a(n) = Sum_{i=0..n} digsum_9(i)^3, where digsum_9(i) = A053830(i).at n=40A231686
- Expansion of q * phi(q)^3 * psi(q^2)^4 in powers of q where phi(), psi() are Ramanujan theta functions.at n=42A243763
- Positive numbers m such that m^2 - 1 divides 2^m - 1.at n=11A247219
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 342", based on the 5-celled von Neumann neighborhood.at n=31A269511