12872
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 24150
- Proper Divisor Sum (Aliquot Sum)
- 11278
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6432
- Möbius Function
- 0
- Radical
- 3218
- Omega Function (Ω)
- 4
- 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
- 76
- 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
- Numbers k such that k, k+1, k+2 and k+3 have the same number of divisors.at n=14A006601
- Number of n-step self-avoiding walks on the 4-dimensional hypercubic lattice with no non-contiguous adjacencies.at n=5A034006
- Let (u1,u2) be successive untouchable numbers such that phi(u1) = phi(u2); sequence gives values of u2.at n=29A048190
- a(n) = Sum_{k=0..n} binomial(8*n,8*k).at n=2A070832
- A measure of how close r^n is to an integer where r is the real root of x^3-x-1, i.e.. r = (1/2 + sqrt(23/108))^(1/3) + (1/2 - sqrt(23/108))^(1/3) = 1.3247.... (Higher absolute value of a(n) means closer, negative means less than closest integer.)at n=59A084252
- Find the shortest prefix of Pi-3 = .141592653589793238462643383279502.. which is divisible by n and divide by n.at n=10A088143
- Duplicate of A070832.at n=2A094212
- Numbers k such that (j^k + k^j) == 0 (mod k+j), j=2 case.at n=6A114977
- a(n) = Sum_{k <= n/2} binomial(n-2k, 3k+2).at n=19A137358
- Number of -5..5 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2).at n=5A199906
- T(n,k)=Number of -k..k arrays x(0..n-1) of n elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2).at n=50A199909
- Number of -n..n arrays x(0..5) of 6 elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2).at n=4A199913
- Number of 0..7 arrays of length n with each element differing from at least one neighbor by 2 or more, starting with 0.at n=5A221514
- T(n,k)=Number of 0..k arrays of length n with each element differing from at least one neighbor by 2 or more, starting with 0.at n=71A221515
- Number of 0..n arrays of length 6 with each element differing from at least one neighbor by 2 or more, starting with 0.at n=6A221517
- a(n) = sum of absolute values of coefficients of a certain polynomial P_n(x) arising in the enumeration of tatami mat coverings.at n=16A226303
- a(n) is the smallest integer that makes A230762(n) the commonest number of decompositions of 2k into an unordered sum of two odd primes, where 3 <= k <= a(n).at n=21A230822
- Numbers n such that (n^n+2^2)/(n+2) is an integer.at n=6A242875
- Compositions of n into parts 3, 4 and 7.at n=43A245368
- Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum 2 4 5 or 7 and every diagonal and antidiagonal sum not 2 4 5 or 7.at n=6A251916