12555
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
- 2
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 23232
- Proper Divisor Sum (Aliquot Sum)
- 10677
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6480
- Möbius Function
- 0
- Radical
- 465
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 107
- 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
- Numbers k that divide the (left) concatenation of all numbers <= k written in base 19 (most significant digit on left).at n=39A029488
- Triangle read by rows giving coefficients of polynomials arising in successive differences of central binomial numbers.at n=17A094796
- Numbers n such that for some k and a_1,a_2,...,a_k the concatenation of the a_i is equal to n and their product is equal to pi(n).at n=43A097221
- Successive powers of the matrix A=[1,2;3,4] written by rows in groups of 4.at n=22A100638
- Row sums of triangle T(j,k) = (j^k) mod (j*k) for 1 <= k <= j (see A096133).at n=44A157351
- Triangular matrix T that satisfies: T^3 - T^2 + I = SHIFT_LEFT(T), as read by rows.at n=37A185620
- Column 1 of triangular matrix T = A185620, which satisfies: T^3 - T^2 + I = SHIFT_LEFT(T).at n=7A185621
- Numbers k such that sopfr(k + omega(k)) = sopfr(k), where sopfr(i) = A001414(i) and omega(i) = A001221(i).at n=15A187878
- Number of n X 2 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, vertically, diagonally or antidiagonally, and top left element zero.at n=5A233020
- Number of nX6 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, vertically, diagonally or antidiagonally, and top left element zero.at n=1A233024
- T(n,k)=Number of nXk 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, vertically, diagonally or antidiagonally, and top left element zero.at n=22A233026
- T(n,k)=Number of nXk 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, vertically, diagonally or antidiagonally, and top left element zero.at n=26A233026
- Numbers that are equal to the arithmetic derivative of their cototient.at n=6A248817
- Expansion of Product_{k>=1} (1 + (k-1)*x^k).at n=24A267007
- Numbers k such that (5*10^k - 173)/3 is prime.at n=16A294727
- a(n) is the maximum water retention of a height-3 length-n number parallelogram with maximum water area.at n=39A303295
- Integers that need 10 iterations of the map x->A352172(x) to reach 1.at n=40A352268
- Starting values k of Collatz orbits that achieve a new minimum of Product_{j == 4 mod 6 in "3x+1" orbit of k} (j-1)/j.at n=18A391017