12380
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 26040
- Proper Divisor Sum (Aliquot Sum)
- 13660
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4944
- Möbius Function
- 0
- Radical
- 6190
- Omega Function (Ω)
- 4
- 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
- 37
- 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
- a(n) = floor(3rd elementary symmetric function of Sum_{j=1..k} 1/j, k = 1,2,...,n).at n=14A025213
- a(n) = (d(n)-r(n))/2, where d = A026063 and r is the periodic sequence with fundamental period (1,1,0,1).at n=42A026064
- First differences of A116084.at n=25A116085
- G.f.: Sum_{n>=0} [Sum_{k=0..n} C(n,k)^2*x^k]^3 * x^n.at n=7A183146
- Number of (1+2) X (n+2) 0..3 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.at n=19A252720
- Number of length-n 0..4 arrays with no repeated value greater than or equal to the previous repeated value.at n=5A269405
- T(n,k)=Number of length-n 0..k arrays with no repeated value greater than or equal to the previous repeated value.at n=41A269409
- Number of length-6 0..n arrays with no repeated value greater than or equal to the previous repeated value.at n=3A269412
- Smallest number k such that A270172(k) = n.at n=32A270173
- Number of triangles on a 4 X n grid.at n=10A296367
- Expansion of 1/(2 + x - theta_2(sqrt(x))/(2*x^(1/8))), where theta_2() is the Jacobi theta function.at n=52A303908
- Total number of Fibonacci parts in all compositions of n.at n=12A309537
- For any k, the cumulative sum a(1) + a(2) + a(3) + ... + a(k) shares at least five digits with a(k). Lexicographically first sequence of positive integers without duplicate terms having this property.at n=16A326640
- Number of sequences of length n that cover an initial interval of positive integers and are both a reversed Lyndon word and a co-Lyndon word.at n=8A334270
- Expansion of g.f. A(x) satisfying A(x) = Sum_{n>=0} d^n/dx^n x^(2*n) * A(x)^(3*n) / n!.at n=4A360975
- a(n) = Sum_{k=0..n} (k+1) * 2^(n-k) * binomial(2*k+1,2*n-2*k).at n=7A391893