17145
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
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 30720
- Proper Divisor Sum (Aliquot Sum)
- 13575
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9072
- Möbius Function
- 0
- Radical
- 1905
- 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
- 172
- 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
- Digitally balanced numbers in base 4: equal numbers of 0's, 1's, ... 3's.at n=35A049355
- Numbers n such that n | 6^n + 5^n + 4^n.at n=44A057235
- Number of compositions of n in which the greatest part is odd.at n=15A103421
- Sequence with a (1,2) Somos-4 Hankel transform.at n=18A178074
- Deficient numbers n having a companion m > n such that sigma(n)/n = sigma(m)/m.at n=30A212608
- Numbers n such that phi(n) = phi(n+12) and n is not divisible by 2.at n=25A217141
- Least m > 0 such that m*n^3 + 1 is a cube.at n=14A266236
- Numbers n in S such that F(n) is prime: see comments for definitions.at n=4A269627
- Expansion of e.g.f. sec(x*tan(x/2)) (even powers only).at n=5A296939
- Triangle read by rows: T(n,k) is the number of n X n binary matrices with k=0..n^2 ones forming a polyomino, under action of dihedral group of the square D_4.at n=47A331462
- a(n) = Sum_{k=0..n-1} (-1)^k * binomial(n,k)^2 * (n-k-1)!.at n=9A352150