16849
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 20160
- Proper Divisor Sum (Aliquot Sum)
- 3311
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13776
- Möbius Function
- -1
- Radical
- 16849
- 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
- 128
- 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 n such that phi(n + 1) | sigma(n) for n congruent to 1 (mod 3).at n=37A015817
- Denominators of continued fraction convergents to sqrt(42).at n=6A041071
- Denominators of continued fraction convergents to sqrt(168).at n=6A041311
- Numerators of continued fraction convergents to sqrt(713).at n=7A042372
- Numbers whose base-7 representation contains exactly four 0's.at n=17A043396
- Consider the Diophantine equation x^3 + y^3 = z^3 - 1 (0 < x < y < z) or 'Fermat near misses'. Arrange solutions by increasing values of z. Sequence gives values of z.at n=18A050787
- a(n) = 2^n - 1 + 2*Fibonacci(n-1).at n=13A060161
- a(n) = 6*binomial(n,4) + 3*binomial(n,3) + 4*binomial(n,2) - n + 2.at n=16A066375
- Upper bound on number of regular triangulations of cyclic polytope C(n, n-4).at n=33A066456
- a(0)=1, a(1)=1, a(n)=7*a(n/2) for n=2,4,6,..., a(n)=6*a((n-1)/2)+a((n+1)/2) for n=3,5,7,....at n=34A116522
- a(n) = n^3 - n^2 - 2*n + 1.at n=26A123972
- Solutions of the Pell-like equation 1 + 6*A*A = 7*B*B, with A, B integers.at n=3A153111
- a(n) = 52*n^2 + 1.at n=18A158644
- Totally multiplicative sequence with a(p) = a(p-1) + 6 for prime p.at n=33A166703
- Number of n X 2 binary arrays with each 1 adjacent to exactly two 0's.at n=12A183330
- Number of n X 4 binary arrays without the pattern 0 1 diagonally or vertically.at n=19A188838
- Triangle of coefficients of polynomials v(n,x) jointly generated with A210864; see the Formula section.at n=40A210865
- Odd numbers m that are neither of the form p + 2^k nor of the form p - 2^k with 2^k < m, k >= 1, and p prime.at n=21A255967
- The x member of the positive proper fundamental solution (x = x2(n), y = y2(n)) of the second class for the Pell equation x^2 - D(n)*y^2 = +8 for odd D(n) = A263012(n).at n=30A264351
- Number of iterations of A268395 needed to reach zero from 2^n: a(n) = A268708(2^n).at n=18A268709