15744
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 42840
- Proper Divisor Sum (Aliquot Sum)
- 27096
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5120
- Möbius Function
- 0
- Radical
- 246
- Omega Function (Ω)
- 9
- 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
- Theta series of direct sum of 2 copies of f.c.c. lattice.at n=27A008663
- Number of ordered quadruples of integers from [ 1,n ] with no common factors between triples.at n=26A015635
- Numbers that are the sum of 4 nonzero squares in exactly 10 ways.at n=45A025366
- Numbers k that divide the (right) concatenation of all numbers <= k written in base 2 (most significant digit on left).at n=41A029447
- First of three consecutive Ulam numbers (A002858) in arithmetic progression with difference 22.at n=7A068856
- a(n) = A062401(2^n + 1).at n=15A096855
- Structured great rhombicosidodecahedral numbers.at n=7A100145
- Bond series for first parallel moment of 4.8 (bathroom tile) lattice.at n=21A120554
- Upper limit palindromic complexity sequence involving Fibonacci numbers.at n=16A129730
- a(n) = n! / A156832(n).at n=40A145500
- Numbers with prime signature {7,1,1}, i.e., of form p^7*q*r with p, q and r distinct primes.at n=19A179696
- G.f.: x = Sum_{n>=1} a(n)*x^n * Sum_{k=0..n} (k+1)*binomial(n,k)*(-x)^k.at n=6A182520
- Coefficient of x in the reduction by x^2 -> x+1 of the polynomial p(n,x) defined below in Comments.at n=8A192384
- Triangle T(n,k) of ways n couples can sit in a row with exactly k of them together.at n=11A193639
- Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of f(i,j) = gcd(i+1, j+1) (A204030).at n=35A204111
- Number of (n+1) X 5 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock differing from each horizontal or vertical neighbor.at n=13A205189
- Number of n X 5 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=12A208376
- Signed partitions of n into n parts in {-n..n} (allowing zero as a part).at n=7A211475
- Number of (w,x,y,z) with all terms in {1,...,n} and 3w>=x+y+z+n.at n=17A212250
- a(n) is the smallest number that requires at least n adjacent bit swaps in order to pack all the ones to the right.at n=46A243112