15533
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 18126
- Proper Divisor Sum (Aliquot Sum)
- 2593
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13272
- Möbius Function
- 0
- Radical
- 2219
- 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
- 53
- 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 (1/theta_4 - 1)/2.at n=25A014968
- a(n) is the number of integer strings s(0),...,s(n) counted by array T in A026374 that have s(n)=2; also a(n) = T(2n,n-1).at n=6A026376
- Numerators of continued fraction convergents to sqrt(657).at n=9A042262
- T(n,n+2), array T given by A047020.at n=8A047027
- McKay-Thompson series of class 42d for Monster.at n=52A058678
- Integers n > 10583 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 10583.at n=6A066055
- A smoothed version of A091587.at n=9A091588
- Triangle, read by rows, of trinomial coefficients arranged so that there are n+1 terms in row n by setting T(n,k) equal to the coefficient of z^k in (1 + 3*z + z^2)^(n-[k/2]), for n>=k>=0, where [k/2] is the integer floor of k/2.at n=61A099512
- Triangle read by rows: T(n,k) is the number of Schroeder paths of length 2n and having k peaks at even height.at n=29A101895
- Riordan array (1/sqrt(1-6x+5x^2),(1-3x-sqrt(1-6x+5x^2))/(2x)).at n=29A110165
- Beginning with 3, least number such that concatenation of first n terms and its digit reversal both are primes.at n=34A111382
- The first 10 digits of the cube root of n contain the digits 0-9.at n=4A119517
- Number of different ways to select 3 disjoint subsets from {1..n} with equal element sum.at n=13A164934
- Irregular triangle T(n,k), n>=1, 1<=k<=ceiling(n/2), read by rows: T(n,k) is the number of different ways to select k disjoint (nonempty) subsets from {1..n} with equal element sum.at n=51A196231
- Number of partitions of n having standard deviation σ > 3.at n=38A238655
- Triangle read by rows, T(n,k) = GegenbauerC(m,-n,-3/2) where m = k if k<n else 2*n-k, for n>=0 and 0<=k<=2n.at n=55A272866
- Triangle read by rows, T(n,k) = GegenbauerC(m,-n,-3/2) where m = k if k<n else 2*n-k, for n>=0 and 0<=k<=2n.at n=57A272866
- Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of e.g.f. exp(k*x)*BesselI(1,2*x).at n=62A292628
- Solution (a(n)) of the complementary equation a(n) = 2*a(n-1) - a(n-2) + b(n-2); see Comments.at n=42A305329
- a(n) equals the coefficient of x^n in Sum_{m>=0} (x^m + 3 + 1/x^m)^m for n >= 1.at n=6A316593