15644
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 27384
- Proper Divisor Sum (Aliquot Sum)
- 11740
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7820
- Möbius Function
- 0
- Radical
- 7822
- Omega Function (Ω)
- 3
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 84
- 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) = Sum_{i=0..n} T(i,n-i), array T as in A049735.at n=19A049736
- Numbers k such that (k+3, k+5, k+17, k+257, k+65537) are all primes.at n=15A063799
- a(n) = n^3 plus sum of digits of n^3.at n=24A123135
- a(n) = a(n-1) + 6*a(n-2) for n >= 2, a(0)=1, a(1)=2.at n=9A133467
- Expansion of Product_{k>0} (1 - x^k)^(2^(k-1)) in powers of x.at n=19A200751
- Number of nX3 0..1 arrays with no element less than a strict majority of its horizontal, vertical and antidiagonal neighbors.at n=5A231539
- Number of nX6 0..1 arrays with no element less than a strict majority of its horizontal, vertical and antidiagonal neighbors.at n=2A231542
- T(n,k)=Number of nXk 0..1 arrays with no element less than a strict majority of its horizontal, vertical and antidiagonal neighbors.at n=30A231544
- T(n,k)=Number of nXk 0..1 arrays with no element less than a strict majority of its horizontal, vertical and antidiagonal neighbors.at n=33A231544
- Number of (n+2) X (3+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 1 and no antidiagonal sum 2 and no row sum 0 and no column sum 3.at n=32A255796
- Number of unlabeled rooted trees with n nodes where the branches of no non-leaf branch of any terminal subtree form a submultiset of the branches of the same subtree.at n=13A324844
- Number of compositions of n whose run-lengths are all different.at n=26A329739
- Dirichlet convolution of A276086 (primorial base exp-function) with A055615 (Dirichlet inverse of n).at n=52A383286