17019
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 25792
- Proper Divisor Sum (Aliquot Sum)
- 8773
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10800
- Möbius Function
- 0
- Radical
- 5673
- Omega Function (Ω)
- 4
- 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
- 159
- 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
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 19 ones.at n=11A031787
- a(n) = (2*n+1) * (4*n-1).at n=46A033566
- Digitally balanced numbers in base 4: equal numbers of 0's, 1's, ... 3's.at n=25A049355
- Numbers n such that h(n) = 2 h(n-1) where h(n) is the length of the sequence {n, f(n), f(f(n)), ...., 1} in the Collatz (or 3x + 1) problem. (The earliest "1" is meant.)at n=19A078419
- Smallest multiple of the n-th prime such that every partial sum is a square.at n=17A085039
- Triangle read by rows: T(n,k) (0<=k<=n) is the number of Schroeder paths of length 2n, having k (1,0)-steps on the lines y=0 and y=1 (a Schroeder path of length 2n is a path from (0,0) to (2n,0), consisting of steps U=(1,1), D=(1,-1) and H=(2,0) and never going below the x-axis).at n=49A110189
- Nine times hexagonal numbers: a(n) = 9*n*(2*n-1).at n=31A152994
- Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 4,1 5,1 6,2 7,2 polyhexes in any orientation on a planar nXnXn triangular grid.at n=7A155419
- Expansion of Sum_{i>=1} x^(i^3) / (1 - Sum_{j>=1} x^(j^3))^2.at n=36A281809
- Numbers m such that m | A000385(m-1) = Sum_{k=1..m-1} sigma(k) * sigma(m-k).at n=22A326608