17900
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 39060
- Proper Divisor Sum (Aliquot Sum)
- 21160
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7120
- Möbius Function
- 0
- Radical
- 1790
- Omega Function (Ω)
- 5
- 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
- 141
- 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
- Partial sums of n + Fibonacci(n+1).at n=19A081662
- Number of zig-zag paths from top to bottom of a rectangle of width 9 with n rows.at n=12A153362
- From the enumeration of hyperbolic manifolds without annular cusps (see reference for precise definition).at n=3A163971
- a(n) = Least i in range [A165598(n),A165598(n+1)] for which abs(A165597(i)) gets the maximum value in that range.at n=22A165599
- Omit the initial 1 from A000141 and take the Mobius transform.at n=44A190622
- Numbers n such that n+(n+1), n^2+(n+1)^2, n+(n+1)^2, n^2+(n+1) are all prime.at n=25A216270
- Triangle read by rows: coefficients of polynomials Q_n(x) arising in study of Riemann zeta function.at n=19A217940
- sigma(n) is an additive inverse of n modulo phi(n).at n=16A235989
- a(n) = n*(n + 1)*(7*n + 11)/6.at n=24A255687
- Numbers k such that the sum of digits of k^2 is 10.at n=42A262713
- Start with the triangle with 4 markings of the Shield tiling and recursively apply the substitution rule. a(n) is the number of triangles with 4 markings after n iterations.at n=9A298682
- Numbers such that the sum of divisors divides the concatenation (in ascending order) of divisors.at n=15A308486
- Expansion of Product_{k>=1} 1/(1 - x^k)^((3*k+1)*binomial(k+2,3)/4).at n=8A317017
- Number of edge-connected components of polygonal cells in the pinwheel tiling up to rotation of the tiling.at n=8A385265