13566
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 34560
- Proper Divisor Sum (Aliquot Sum)
- 20994
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3456
- Möbius Function
- -1
- Radical
- 13566
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 5
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 182
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Stirling numbers of the first kind: s(n+2, n).at n=17A000914
- Self-convolution 4th power of A001764, which enumerates ternary trees.at n=6A006629
- Stirling numbers of first kind S1(19,n).at n=16A011529
- Number of rooted noncrossing trees with n nodes such that root has degree 1 and the child of the root has degree at least 2.at n=6A030983
- "DIJ" (bracelet, indistinct, labeled) transform of 2,2,2,2,...at n=6A032266
- Distinct even numbers in writing first numerator and then denominator of each element of the 1/4-Pascal triangle (by row).at n=19A046589
- T(n,n-3), array T given by A047000.at n=8A047005
- (Terms in A014476)/2.at n=48A051497
- Number of symmetric types of (3,2n)-hypergraphs under action of complementing group C(3,2).at n=34A055780
- McKay-Thompson series of class 28A for Monster.at n=32A058606
- Generalized sum of divisors function: third diagonal of A060047.at n=32A060046
- Second level generalization of Catalan triangle (0th level is Pascal's triangle A007318; first level is Catalan triangle A009766; 3rd level is A069270).at n=51A069269
- Triangle read by rows of numbers of paths in a lattice satisfying certain conditions.at n=34A071948
- Triangle of numbers {a(n,k), n >= 0, 0<=k<=n} defined by a(0,0)=1, a(n,0)=A001764(n), a(n,n)=A006013(n), a(n,n-1)=A006629(n-1).at n=34A073147
- Treated as strings, phi(n) is a substring of sigma(n).at n=23A074452
- Squarefree balanced numbers (i.e., squarefree members of A020492).at n=30A078557
- Triangle read by rows: T(n,k) is the number of noncrossing trees with root degree equal to k.at n=29A092276
- Sequence resulting from a sum of three repeated binomial(n+3,4) sequences.at n=33A093039
- Least area of primitive Pythagorean triangle whose legs differ by A058529(n).at n=32A094143
- Consider a Pythagorean triangle with sides a=u^2-v^2, b=2uv, c=u^2+v^2. The sequence is the area of the triangle when v=2, u=3,4,5,...at n=16A096382