12989
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13440
- Proper Divisor Sum (Aliquot Sum)
- 451
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12540
- Möbius Function
- 1
- Radical
- 12989
- 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
- 50
- 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
- One half of number of non-self-conjugate partitions; also half of number of asymmetric Ferrers graphs with n nodes.at n=38A000701
- a(n) = n*(27*n + 1)/2.at n=31A022285
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (composite numbers), t = (primes).at n=26A024604
- Number of partitions of n into an odd number of parts.at n=38A027193
- First differences of A037260.at n=35A037261
- Numbers k such that sigma(k) divides sigma(phi(k)).at n=39A066831
- Numbers n such that sigma(phi(n))/sigma(n) = 3.at n=5A067383
- 7th binomial transform of (0,1,0,2,0,4,0,8,0,16,...).at n=5A081184
- Record values in A079300 (number of shortest addition chains of n).at n=13A118387
- Odd winning positions in Fibonacci nim.at n=24A120904
- Record values in A062039.at n=50A123643
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (0, 1, 1), (1, 0, -1), (1, 1, 1)}.at n=7A150847
- Number of strings of numbers x(i=1..4) in 0..n with sum i*x(i) equal to n*4.at n=38A184704
- Number of partitions of 2n of type EO (see Comments).at n=19A236559
- Expansion of 1/G(1) where G(k) = 1 - (q/(1-q))^k / G(k+1).at n=11A238435
- Coefficient of x^2 in minimal polynomial of the continued fraction [1^n,sqrt(5),1,1,1,...], where 1^n means n ones.at n=9A266705
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 489", based on the 5-celled von Neumann neighborhood.at n=25A272512
- Number of integer partitions of n with reverse-alternating product > 1.at n=38A347449