11889
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 17186
- Proper Divisor Sum (Aliquot Sum)
- 5297
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7920
- Möbius Function
- 0
- Radical
- 3963
- 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
- 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
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has period 86.at n=32A020425
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 3.at n=30A050051
- Square chains: the number of permutations (reversals not counted as different) of the numbers 1 to n such that the sum of any two consecutive numbers is a square.at n=23A071983
- Number of compositions (ordered partitions) of n into powers of 3.at n=25A078932
- Satisfies A(x) = f(x) + x*A(x)*f(x)^2, where f(x) = Sum_{k>=0} x^((3^n-1)/2) and f(x)^2 = 2 - f(x^2) + 2*Sum_{n>0} x^A023745(n). Also, A(x) = f(x)*B(x), where B(x) = Sum_{k>=0} A087218(k)*x^k.at n=12A087219
- a(n) = (2*a(n-1)*a(n-3) + a(n-2)^2)/a(n-4), with a(1)=..=a(4)=1.at n=9A121883
- Appearance radii of visible vectors in the medial axis test mask for the Euclidean distance in Z^2.at n=16A171988
- A185243(n) is the a(n)-th triangular number.at n=45A185257
- Number of length 3 1..(n+1) arrays with every leading partial sum divisible by 2, 3, 5 or 7.at n=28A258634
- Numbers m such that the proportion of nonsquarefree numbers in the interval [1, m] is greater than the corresponding proportion for all k > m.at n=27A336026
- Numbers k such that lcm(1,2,3,...,k)/23 equals the denominator of the k-th harmonic number H(k).at n=8A342351
- a(n) = Sum_{1 <= i, j, k <= n} gcd(i,j,k).at n=20A344522
- Starts of runs of 3 consecutive integers that are all terms in A381581.at n=36A381583