11817
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
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 18564
- Proper Divisor Sum (Aliquot Sum)
- 6747
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7200
- Möbius Function
- 0
- Radical
- 3939
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 81
- 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
- Expansion of e.g.f. log(1+x)/cosh(tan(x)).at n=9A009433
- Numbers whose set of base-14 digits is {1,4}.at n=28A032826
- Triangles in open triangular matchstick arrangement (triangle minus one side) of side n.at n=36A045947
- Number of ways to color vertices of a pentagon using <= n colors, allowing only rotations.at n=9A054620
- Number of n-bead necklaces with 9 colors.at n=5A054628
- T(n,k) = Sum_{d|k} phi(d)*n^(k/d)/k, triangle read by rows, T(n,k) for n >= 1 and 1 <= k <= n.at n=40A054630
- Number of partitions of the n-th abundant number into abundant numbers.at n=55A097800
- a(n) = floor(n*(n+2)*(n+4)*(n-6)/192).at n=39A117652
- a(n) = n*(4*n^2 + n - 1)/2.at n=17A125200
- a(1) = 1; for n>1, a(n) = a(n-1)*b(n-1) + 1, where {b(k)} is the concatenated list of the ordered positive divisors of the terms of {a(k)}.at n=11A129645
- Concatenated list of the positive divisors of the terms of sequence A129645.at n=51A129646
- Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1110-0111 pattern in any orientation.at n=9A146822
- Numbers n which are concatenations n=x//y such that x^2+y^3 is a multiple of n.at n=28A162464
- Number of partitions of n containing a clique of size 10.at n=42A183567
- Number of -3..3 arrays of n elements with first and second differences also in -3..3.at n=5A201083
- T(n,k)=Number of -k..k arrays of n elements with first and second differences also in -k..k.at n=33A201088
- Number of -n..n arrays of 6 elements with first and second differences also in -n..n.at n=2A201091
- Number of partitions of n into distinct parts with boundary size 6.at n=44A227563
- a(n) = Fibonacci(p) mod p^2, where p = prime(n).at n=46A236395
- Sum of the next to smallest parts in the partitions of 4n into 4 parts with smallest part = 1.at n=26A239195