17505
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
- 30420
- Proper Divisor Sum (Aliquot Sum)
- 12915
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9312
- Möbius Function
- 0
- Radical
- 5835
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 79
- 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
- Coordination sequence for 6-dimensional lonsdaleite.at n=9A008526
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite RTH = RUB-13 [B2Si30O64].2R starting with a T1 atom.at n=13A019226
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (odd natural numbers), t = (primes).at n=29A025117
- Numbers whose base-4 representation has exactly 8 runs.at n=9A043599
- Numbers n such that number of runs in the base 4 representation of n is congruent to 1 mod 7.at n=30A043844
- Numbers n such that number of runs in the base 4 representation of n is congruent to 0 mod 8.at n=9A043850
- Numbers n such that number of runs in the base 4 representation of n is congruent to 8 mod 9.at n=9A043866
- Numbers k such that number of runs in the base 4 representation of k is congruent to 8 mod 10.at n=9A043875
- a(n+1)-+a(n)=prime, a(n+1)*a(n)=Average of twin prime pairs, a(1)=3,a(2)=10.at n=28A154496
- Triangle read by rows: T(n,k) is the number of cycle-up-down permutations of {1,2,...,n} having k fixed points (0 <= k <= n). A permutation is said to be cycle-up-down if it is a product of up-down cycles. A cycle (b(1), b(2), ...) is said to be up-down if, when written with its smallest element in the first position, it satisfies b(1) < b(2) > b(3) < ... .at n=46A186363
- Monotonic ordering of set S generated by these rules: if x and y are in S then floor(x*y/2) is in S, and 5 is in S.at n=36A192520
- Equals one maps: number of n X n binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal and antidiagonal neighbors in a random 0..1 n X n array.at n=3A220573
- Equals one maps: number of nX4 binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal and antidiagonal neighbors in a random 0..1 nX4 array.at n=3A220575
- T(n,k)=Equals one maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal and antidiagonal neighbors in a random 0..1 nXk array.at n=24A220579
- Equals one maps: number of 4Xn binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal and antidiagonal neighbors in a random 0..1 4Xn array.at n=3A220582
- Numbers n such that n!!-8 is prime.at n=24A259359
- Expansion of Product_{k>=1} (1 + 2*x^k)/(1 - x^k).at n=18A264686
- Numbers k such that 16*10^k + 1 is prime.at n=29A273002
- Number of vertices in a polygon whose boundary consists of n+2 equally spaced points around a semicircle and n+2 equally spaced points along the diameter (a total of 2n+2 points). See Comments for precise definition.at n=14A334458