16804
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 29414
- Proper Divisor Sum (Aliquot Sum)
- 12610
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8400
- Möbius Function
- 0
- Radical
- 8402
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 66
- 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
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 74 ones.at n=16A031842
- Becomes prime after n iterations of f(x) = sigma(x)-1 (least inverse of A039655).at n=24A039656
- Numbers whose base-7 representation contains exactly four 6's.at n=28A043420
- Row sums of triangle A131948.at n=14A131949
- Difference between largest number of complexity n in the sense of A005245 and smallest number of complexity n in the sense of A005245.at n=26A133374
- Monotonic ordering of nonnegative differences 7^i-3^j, for 40>= i>=0, j>=0.at n=28A192154
- Sum of rows of the triangle in A080381.at n=16A202148
- Number of (w,x,y) with all terms in {0,...,n} and w != min(|w-x|, |x-y|, |y-w|).at n=25A213492
- Number of boundary guillotine partitions of a 4-dimensional box obtained with n cuts.at n=5A220876
- Expansion of 1/(1 - x^3 - x^4 - x^5 - x^6 + x^9).at n=36A225484
- The number of permutations in S_n for which the number of reduced words is maximized with respect to the numbers of braid and commutation classes: |R(w)| = |B(w)| * |C(w)|.at n=9A290953
- List of numbers n such that A039655(n) reaches a new record high.at n=11A292114
- Expansion of g.f.: f'(t)/f(t), where f(t) = Sum_{p prime} t^p.at n=21A307977
- For 0 <= R <= 255, let s(R,n) = eventual period of a single cell in a Rule R cellular automaton operating in a cyclic universe of width n; a(n) is the nearest integer to max_R s(R,n)/n (rounded down in case of ties).at n=20A334500
- Fourier coefficients of the modular form (1/t_{3A}) * F_{3A}^16.at n=4A341561
- Square array T(n, k) (n>=1, k>=1) read by antidiagonals upwards. T(n, k) is the number of partitions of the set [n] into lists of k noncrossing sets.at n=58A348702
- Number of length-n binary strings having a string attractor of size at most 2.at n=19A355520
- a(n) = Sum_{k=0..floor(n/3)} binomial(n-1-2*k,n-3*k) * binomial(2*k,k).at n=18A360309
- Array read by downward antidiagonals: A(n,k) = (k+1)^2*A(n-1,k) + A(n-1,k+1) with A(0,k) = 1, n >= 0, k >= 0.at n=25A369527