15586
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 23382
- Proper Divisor Sum (Aliquot Sum)
- 7796
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7792
- Möbius Function
- 1
- Radical
- 15586
- 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
- 102
- 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
- yes
- Odd
- no
Appears in sequences
- Number of binary sequences of length n with an even number of ones, at least two of the ones being contiguous.at n=14A027711
- Consider the trajectory of n under the iteration of a map which sends x to 3x - sigma(x) if this is >= 0; otherwise the iteration stops. The sequence gives values of n which eventually reach 0.at n=35A037159
- Number of ways to tile an n X 1 strip with 1 X 1 squares and 2 X 1 dominoes with the restriction that no three consecutive tiles are of the same type.at n=30A137200
- n^2 + {1,3,7} are primes.at n=39A182238
- Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having two, three, four or five distinct values for every i,j,k<=n.at n=9A211571
- Beach-Williams Pell numbers of type 2p (p prime).at n=12A212074
- Number of binary arrays of length n+11 with no more than 6 ones in any length 12 subsequence (=50% duty cycle).at n=3A212400
- T(n,k)=Number of binary arrays of length n+2*k-1 with no more than k ones in any length 2k subsequence (=50% duty cycle).at n=39A212402
- Number of binary arrays of length 2*n+3 with no more than n ones in any length 2n subsequence (=50% duty cycle).at n=5A212405
- Number of partitions of n in which any two parts differ by at most 10.at n=38A218512
- Number of length n+3+1 0..3 arrays with every value 0..3 appearing at least once in every consecutive 3+2 elements, and new values 0..3 introduced in order.at n=11A242234
- Number of length n+5 0..1 arrays with at most one downstep in every n consecutive neighbor pairs.at n=38A255996
- Sum of the smallest parts of the partitions of n into 10 parts.at n=48A326589
- a(n) is the end square spiral number for a knight starting on square n moving on a board with squares numbered with the square of their distance from the 0-square origin and where the knight moves to the smallest numbered unvisited square; the smallest spiral number ordering is used if the distances are equal.at n=31A326931
- a(n) is the least number which is coprime to its digital sum (A339076) with a gap n to the next term of A339076, or 0 if such a number does not exist.at n=6A339078
- Numbers that are the sum of seven fourth powers in six or more ways.at n=3A345572
- Numbers that are the sum of seven fourth powers in exactly six ways.at n=3A345828
- a(n) is the result of n applications of the function f on n, where f(x) = floor((3*x - 1)/2) (A001651).at n=17A353215