9231
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13104
- Proper Divisor Sum (Aliquot Sum)
- 3873
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5760
- Möbius Function
- -1
- Radical
- 9231
- 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
- 91
- 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
- Expansion of 1/((1 - x)*(1 - 4*x + 2 * x^2)).at n=7A035344
- G.f.: (1 + Sum_{ i >= 0 } 2^i*x^(2^(i+1)-1)) / (1-x)^3.at n=40A063916
- Take pairs (a, b), sorted on a, such that T(a)+T(b)=concatenation of a and b, where T(k) is the k-th triangular number A000217(k). Sequence gives values of b.at n=14A096032
- Take pairs (a, b), sorted on a, such that T(a)+T(b)=concatenation of a and b, where T(k) is the k-th triangular number A000217(k). Sequence gives values of b.at n=24A096032
- Coefficients of the D-Dyson mod 27 identity.at n=37A104504
- G.f.: A(x) = ( G(x)^5 - G(x^5) - 5*x*((1-x^4)/(1-x))/(1-x^5) )/(25*x^2) where G(x) is the g.f. of A110631.at n=13A111583
- a(n) = smallest number m such that in 1,2,..,m written in base n, no two of the n digits occurs the same number of times.at n=7A152925
- Sum_{k=1,...,2n} (-1)^k binomial(8*n,4*k).at n=1A232719
- Number of partitions p of n such that (number of even numbers in p) >= (number of odd numbers in p).at n=36A241639
- Expansion of Product_{k>=1} 1/(1-x^(k+6))^k.at n=39A263362
- Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 5 or 6 king-move adjacent elements, with upper left element zero.at n=11A304664
- Squares where knight moving to a lowest unvisited square on a spirally numbered board will have no available moves.at n=10A323714
- Number of integer partitions y of n such that Product_{i in y} prime(i)/i is an integer.at n=54A324925
- For a positive number k, let L(k) denote the list consisting of k followed by the prime factors of k, with repetition, in nondecreasing order; sequence gives composite k such that the digits of L(k) alternate being smaller than and then larger than the previous digit.at n=50A372336
- a(n) = Sum_{1 <= x_1, x_2, x_3 <= n} sigma( n/gcd(x_1, x_2, x_3, n) ).at n=8A373130