16219
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
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 18924
- Proper Divisor Sum (Aliquot Sum)
- 2705
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13860
- Möbius Function
- 0
- Radical
- 2317
- 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
- 190
- 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
- no
- Odd
- yes
Appears in sequences
- Pseudoprimes to base 31.at n=42A020159
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 31 ones.at n=3A031799
- Numerators of continued fraction convergents to sqrt(804).at n=5A042550
- Composite numbers k such that the sum of the proper divisors of k not including 1, (Chowla's function, A048050) and their product (A007956) are both perfect squares.at n=37A064180
- Number of permutations of length n which avoid the patterns 1234, 2143, 3421.at n=23A116842
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, -1), (1, -1, 0), (1, 0, 1), (1, 1, -1)}.at n=9A148813
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (0, 1, 0), (0, 1, 1), (1, 0, 0), (1, 1, -1)}.at n=7A151077
- Number of (w,x,y,z) with all terms in {1,...,n} and w^2>x*y*z.at n=18A212066
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-2) + n, where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4.at n=16A293349
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1) + b(n-2) + n + 1, where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences.at n=15A294556
- L.g.f.: log(Product_{k>=1} (1 + x^k/(1 - x))) = Sum_{k>=1} a(k)*x^k/k.at n=52A307761
- Partial sums of A175046.at n=41A324127
- Three-column array giving list of primitive triples for integer-sided triangles with A < B < C < 2*Pi/3 and such that FA, FB, FC are also integers where F is the Fermat point of the triangle.at n=18A352360
- a(n) = Sum_{k=1..n} binomial(floor(n/k)+2,3).at n=41A364970
- Expansion of the o.g.f. A(x) defined by [x^n] A(x)^(6*n) = (3*n)!/n!^3 for n >= 0.at n=6A377217
- Numerators of the convergents given by treating A072193 as continued fraction coefficients after the leading 0.at n=10A391714