12869
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13644
- Proper Divisor Sum (Aliquot Sum)
- 775
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12096
- Möbius Function
- 1
- Radical
- 12869
- Omega Function (Ω)
- 2
- 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
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Euler characteristics of polytopes.at n=16A006482
- 7-dimensional centered tetrahedral numbers.at n=8A008501
- Central binomial coefficient - 1.at n=16A014495
- Number of distinct prime signatures of the positive integers up to 2^n.at n=50A025488
- Number of combinations of n things from 1 to n at a time, with repeats allowed.at n=7A030662
- Square root of A030681.at n=37A030682
- Base-3 digits are, in order, the first n terms of the periodic sequence with initial period 1,2,2.at n=8A037544
- Number of 2n-bead balanced binary necklaces of fundamental period 2n equivalent to reverse.at n=17A045680
- Array read by antidiagonals upwards: h(n,k) = number of sequences with n copies each of 1,2,...,k and longest increasing subsequence of length k (n>=1, k>=1).at n=37A047909
- T(n, k) = S(2n, n, k) for 0<=k<=n and n>=0, where S(p, q, r) is the number of upright paths from (0, 0) to (p, p-q) that do not rise above the line y = x-r.at n=43A050157
- Numbers k such that k^2 contains only digits {1,5,6}.at n=8A053902
- Triangle T(n,k) read by rows: number of lattice paths from (0,0) to (0,2n) with steps (1,1) or (1,-1) that stay between the lines y=0 and y=k.at n=43A101475
- Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 110-111-010 pattern in any orientation.at n=9A146247
- a(n) = binomial(n+8,8) - 1.at n=8A165618
- Ordered differences of central binomial coefficients.at n=28A205008
- Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and 2w+x+y>1.at n=15A211618
- G.f.: Sum_{n>=0} ((1+x)^n - 1)^n / (1+x)^(n^2).at n=6A220352
- Number of permutations of [n] having a shortest ascending run of length 8.at n=8A228675
- Smallest k<3*2^n such that 3*2^n+k is the smallest of four consecutive primes in arithmetic progression or 0 if no solution.at n=35A230852
- Number of standard Young tableaux with n cells such that the lengths of the first and the last row differ by 1.at n=10A244295