13555
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16272
- Proper Divisor Sum (Aliquot Sum)
- 2717
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10840
- Möbius Function
- 1
- Radical
- 13555
- Omega Function (Ω)
- 2
- 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
- 89
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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
- A Fielder sequence.at n=15A001642
- a(n+1) = a(n) converted to base 9 from base 8 (written in base 10).at n=40A023391
- a(n) = floor( Sum_{1 <= i < j <= n} ((sqrt(j)-sqrt(i))^3) ).at n=41A025197
- a(n+2) = F(n+1)*a(n+1) + F(n)*a(n) where F(n) = Fibonacci number (A000045), a(0) = a(1) = 1.at n=8A089126
- Poincaré series [or Poincare series] (or Molien series) for a certain four-fold wreath product P_4.at n=47A091434
- Integer part of the area of consecutive prime sided isosceles triangles.at n=39A097442
- The number of n-almost primes less than or equal to e^n, starting with a(0)=1.at n=26A116432
- Number of (n+1)X2 0..7 arrays with the permanents of all 2X2 subblocks equal and nonzero.at n=1A204784
- Number of (n+1)X3 0..7 arrays with the permanents of all 2X2 subblocks equal and nonzero.at n=0A204785
- T(n,k)=Number of (n+1)X(k+1) 0..7 arrays with the permanents of all 2X2 subblocks equal and nonzero.at n=1A204791
- T(n,k)=Number of (n+1)X(k+1) 0..7 arrays with the permanents of all 2X2 subblocks equal and nonzero.at n=2A204791
- Number of -3..3 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having one, two, three, four, five or six distinct values for every i,j,k<=n.at n=4A211736
- a(n) = floor(M(g(n-1)+1, ..., g(n))), where M = harmonic mean and g(n) = n^3 + n^2 + n + 1.at n=23A227015
- Number of partitions p of n such that the number of parts is a part and max(p) - min(p) is not a part.at n=47A241384
- Multiplicity of the zero at x=1 of the characteristic polynomial P_n^C.at n=27A246997
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 486", based on the 5-celled von Neumann neighborhood.at n=32A272508
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 846", based on the 5-celled von Neumann neighborhood.at n=34A273689
- Numbers k such that k!4 + 2^10 is prime, where k!4 = k!!!! is the quadruple factorial number (A007662).at n=29A291351
- G.f. satisfies A(x) = (1 + x) * (1 + x*A(x)^5).at n=5A364338
- Array read by antidiagonals: T(m,n) (m >= 1, n >= 1) = number of reduced connected row convex (RCRC) constraints between an m-element set and an n-element set.at n=39A372066