16643
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
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19440
- Proper Divisor Sum (Aliquot Sum)
- 2797
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 14080
- Möbius Function
- -1
- Radical
- 16643
- Omega Function (Ω)
- 3
- 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
- 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
- no
- Odd
- yes
Appears in sequences
- Numbers that are the sum of 6 positive 7th powers.at n=30A003373
- a(0) = 1, a(n) = 9*n^2 + 2 for n>0.at n=43A010002
- Poincaré series [or Poincare series] for depths of roots in a certain root system.at n=20A019528
- Sum of squares of digits of n is equal to the largest prime factor of n reversed, where the largest prime factor is not a palindrome.at n=26A074303
- 1/4 the number of (n+1) X 3 binary arrays with all 2 X 2 subblock sums the same.at n=14A183979
- Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 197", based on the 5-celled von Neumann neighborhood.at n=32A286648
- p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 3 S + S^2.at n=7A291415
- Solution of the complementary equation a(n) = a(n-1) + 3*a(n-2) -2*a(n-3) - 2*a(n-4) + b(n-3), where a(0) = 1, a(1) = 2, a(2) = 3, a(3) = 4, b(0) = 5, b(1) = 6, b(2) = 7, b(3) = 8, and (a(n)) and (b(n)) are increasing complementary sequences.at n=16A295621
- Numbers that are the sum of 4 nonzero 4th powers in more than one way.at n=32A309763
- Square array A(n,k), n >= 1, k >= 0, read by antidiagonals: A(n,k) = Sum_{d|n} sigma_k(d).at n=58A322103
- Setwise difference A340150 \ A340076.at n=37A340151
- Numbers that are the sum of four fourth powers in exactly two ways.at n=31A344193
- Numerators of the partial sums of the reciprocals of the number of abelian groups function (A000688).at n=50A379359