13446
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
- 4
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 30492
- Proper Divisor Sum (Aliquot Sum)
- 17046
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4428
- Möbius Function
- 0
- Radical
- 498
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 3
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
- 45
- 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
- yes
- Odd
- no
Appears in sequences
- Incomplete Gamma Function at -3.at n=9A010843
- Self-convolution of row n of array T given by A026552.at n=6A027272
- Denominators of continued fraction convergents to sqrt(420).at n=5A041799
- Trajectory of 3 under map n->7n-1 if n odd, n->n/2 if n even.at n=22A063871
- Least common multiple of prime(n+1)-1 and prime(n)-1.at n=37A083554
- Numbers n with digits in nondecreasing order such that sum of the reciprocal of digits is an integer.at n=28A091784
- Number of points of self-intersection of the path of a billiard ball traveling at a 45-degree angle on a prime(n) X prime(n+1) billiard table. Also equal to 1/2 the number of the lattice points lying within a prime(n) X prime(n+1) rectangle.at n=37A099407
- Indices of primes in sequence defined by A(0) = 71, A(n) = 10*A(n-1) + 81 for n > 0.at n=21A101154
- Even terms in A118854.at n=5A118855
- a(n)=3*a(n-1)+12*a(n-2) for n>=3, a(0)=1, a(1)=3, a(2)=18 .at n=6A133594
- G.f.: (21 + 101*x + 97*x^2 + 22*x^3 + x^4)/(1 - x)^5.at n=5A160769
- Number of ways of writing n as the sum of 9 triangular numbers.at n=16A226253
- Number of (n+1) X (n+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).at n=4A235079
- Number of (n+1) X (5+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).at n=4A235084
- T(n,k) is the number of (n+1) X (k+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).at n=40A235087
- Number of partitions p of n such that (maximal multiplicity of the parts of p) < (number of distinct parts of p).at n=39A240305
- Number of partitions p of n such that (number of even numbers in p) <= 2*(number of odd numbers in p).at n=35A241642
- Number of nX5 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=5A281397
- T(n,k)=Number of nXk 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=50A281400
- Number of 6 X n 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=4A281405