12261
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 16864
- Proper Divisor Sum (Aliquot Sum)
- 4603
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7920
- Möbius Function
- -1
- Radical
- 12261
- Omega Function (Ω)
- 3
- 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
- 156
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Numerators of convergents to A058914.at n=23A048817
- a(n) = 3*(2^n-1) - 2*n.at n=12A050488
- Expansion of (1-x)^(-1)/(1 - x - 2*x^2 + 2*x^3).at n=22A077866
- Output of the linear congruential pseudo-random number generator used in function rand() as described in Kernighan and Ritchie, when seeded with 0.at n=10A096554
- a(n) = 2*a(n-1) - a(n-2) + n + 1.at n=40A121968
- a(n) = 6*2^n - 2*n - 5.at n=11A142964
- X-toothpick sequence on Z^3 lattice (see Comments for precise definition).at n=32A160170
- Number of 2 X 2 matrices with all terms in {0,1,...,n} and (sum of terms) = n + 4.at n=36A210376
- Conjecturally, the largest k such that prime(n)^2 is the largest squared prime divisor of binomial(2k,k).at n=32A239623
- Expansion of Product_{k>=1} 1/(1 - A000009(k)*x^k).at n=19A270995
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 675", based on the 5-celled von Neumann neighborhood.at n=20A273408
- Wiener index for the n-Andrásfai graph.at n=40A292018
- Expansion of (-1 + Product_{k>=1} 1 / (1 + (-x)^k))^5.at n=20A341244
- Expansion of g.f. A(x) satisfying x = P(x) * Sum_{n=-oo..+oo} x^(n*(3*n+1)/2) * (A(x)^(3*n) - 1/A(x)^(3*n+1)), where P(x) = 1/Product_{n>=1} (1 - x^n).at n=7A360580
- Number of integer partitions of n - 1 containing fewer 1's than any other part.at n=45A364159
- On a 2 X n grid of vertices, draw a circle through every unordered triple of non-collinear vertices: a(n) is the number of distinct (finite) regions created.at n=6A384702