10818
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
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 23478
- Proper Divisor Sum (Aliquot Sum)
- 12660
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3600
- Möbius Function
- 0
- Radical
- 3606
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 117
- 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
- High-temperature series in w = tanh(J/kT) for ferromagnetic susceptibility for the spin-1/2 Ising model on hexagonal lattice.at n=6A002920
- Theta series of direct sum of 3 copies of hexagonal lattice.at n=25A008654
- Coordination sequence for C_3 lattice: a(n) = 16*n^2 + 2 (n>0), a(0)=1.at n=26A010006
- Define the sequence S(a(0),a(1)) by a(n+2) is the least integer such that a(n+2)/a(n+1) > a(n+1)/a(n) for n >= 0. This is S(4,12) (agrees with A019481 for n <= 19 only).at n=7A019480
- a(n) = 3*a(n-1) + a(n-2) - 2*a(n-3) (agrees with A019480 for n <= 19 only).at n=7A019481
- Numbers whose set of base-15 digits is {1,3}.at n=27A032922
- a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = n - 1 - 2^p 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) = 1.at n=15A049902
- Triangle T(n,k) read by rows, defined by T(n,k) = (n-k)*T(n-1,k)+Sum(k=1..n, T(n-1,k)); T(1,1) = 1, T(1,k)= 0 if k >1.at n=23A089225
- Indices of primes in sequence defined by A(0) = 67, A(n) = 10*A(n-1) - 33 for n > 0.at n=18A101526
- Coefficients of the A-Dyson Mod 27 identity.at n=34A104501
- Numbers k for which digitsum(k) + digitsum(k^2) + digitsum(k^3) = digitsum(k^4).at n=24A118470
- Multiples of 18 containing a 18 in their decimal representation.at n=24A121038
- Number of (n+2) X (n+2) binary matrices with every 3 X 3 block having exactly four 1's.at n=3A181254
- Number of (n+2)X6 binary matrices with every 3X3 block having exactly four 1's.at n=3A181258
- T(n,k) = number of (n+2) X (k+2) binary matrices with every 3 X 3 block having exactly four 1's.at n=24A181262
- Number of 2 X n arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random 0..1 2 X n array.at n=10A218898
- Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 2 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 2 3 6 or 7.at n=14A252257
- Number of 2X2X2 triangular 0..n arrays with some element plus some adjacent element totalling n+1, n or n-1 exactly once.at n=36A270851
- Number of 4-cycles in the n-triangular honeycomb queen graph.at n=9A289705
- Numbers of the form k^2 + 2 that are the sums of two squares.at n=10A329170