17811
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
- 6
- Divisor Sum
- 25740
- Proper Divisor Sum (Aliquot Sum)
- 7929
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11868
- Möbius Function
- 0
- Radical
- 5937
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 2
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
- 97
- 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
- Numbers k such that 111*2^k-1 is prime.at n=39A050581
- Number of fixed (orientation matters) polyominoids (shapes made of faces of cubes) with n squares.at n=4A075678
- Numbers k such that k and k^2 use only the digits 1, 2, 3, 7 and 8.at n=5A136982
- Number of strip poly-IH68-tiles (holes allowed) with n cells.at n=12A182646
- a(n) = Sum_{k=1..n} k*lcm(k,k')/gcd(k,k'), where k' is arithmetic derivative of k.at n=21A190122
- Number of 0..n arrays of length 6 with each element differing from at least one neighbor by 1 or less, starting with 0.at n=29A221685
- Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 6.at n=21A244535
- Number of partitions of n with product of multiplicities of parts equal to 8.at n=54A266691
- Number of aperiodic necklaces (Lyndon words) with k<=6 black beads and n-k white beads.at n=28A277631
- Irregular triangle read by rows: T(n,k) is the number of k-crossing partitions on 2n nodes, where all partition terms alternate in parity, counted up to reflection.at n=49A368054
- Square array read by descending antidiagonals: A(n,k) is the number of fixed n-dimensional (n,2)-polyominoids, n >= 2, of size k >= 1.at n=16A385715