15844
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 29484
- Proper Divisor Sum (Aliquot Sum)
- 13640
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7424
- Möbius Function
- 0
- Radical
- 7922
- 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
- 53
- 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( Gamma(n+2/9) / Gamma(2/9) ).at n=9A020068
- Row/column pre-periods of Sprague-Grundy values of Wythoff's Game.at n=45A046874
- Consider the version of the Collatz or 3x+1 problem where x -> x/2 if x is even, x -> (3x+1)/2 if x is odd. Define the stopping time of x to be the number of steps needed to reach 1. Sequence gives the number of integers x with stopping time n.at n=35A060322
- a(n) = 8*n^2 + 8*n + 4.at n=44A108099
- Row sums of triangle A129503.at n=35A129504
- 4 times 9-gonal numbers: a(n) = 2*n*(7*n-5).at n=34A152760
- Numbers x such that 0 < |x^4 - y^3| < x^(5/3) for some number y.at n=5A173351
- Numbers n such that there is no square n-gonal number greater than 1.at n=22A188896
- Number of n X 3 binary arrays with every 1 immediately preceded by 0 0 to the left or above.at n=7A203103
- T(n,k)=Number of nXk binary arrays with every 1 immediately preceded by 0 0 to the left or above.at n=47A203108
- T(n,k)=Number of nXk binary arrays with every 1 immediately preceded by 0 0 to the left or above.at n=52A203108
- Number of 4-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero with no three beads in a row equal.at n=27A209345
- Number of (n+1) X (1+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally or vertically.at n=6A232425
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally or vertically.at n=21A232431
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally or vertically.at n=27A232431
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, diagonally or antidiagonally.at n=27A232839
- Numbers n such that the decimal number concat(3,n) is a square.at n=39A273358
- T(n,k) = number of circular arrays of n 1's, n -1's, and k 0's such that no two adjacent elements are equal.at n=41A283614
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n) + 2*n, where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=15A296776
- a(n) = Sum_{k=1..n} (-1)^(k+1) * floor((n/k)^3).at n=25A350222