17345
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 20820
- Proper Divisor Sum (Aliquot Sum)
- 3475
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13872
- Möbius Function
- 1
- Radical
- 17345
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 141
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- EULER transform of 3, 2, 2, 2, 2, 2, 2, 2, ...at n=16A000713
- Expansion of (1-x)/(1 - 3*x + x^2)^2.at n=8A001870
- a(n) = s(1)*s(n) + s(2)*s(n-1) + ... + s(k)*s(n+1-k), where k = floor((n+1)/2), s = (Fibonacci numbers).at n=17A024458
- a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ] and s = (Fibonacci numbers).at n=16A025078
- Recip transform of 2*(1 + x^2 + x^5 + x^6)-1/(1-x).at n=12A049167
- Convolution of Fibonacci F(n+1), n>=0, with F(n+10), n>=0.at n=8A067978
- Polynomial (1/3)*n^3 + (9/2)*n^2 + (85/6)*n - 2.at n=33A073775
- Convoluted convolved Fibonacci numbers G_j^(2).at n=17A089089
- Sign twisted convoluted convolved Fibonacci numbers H_j^(2).at n=17A089098
- Number of 0's in odd position in all Fibonacci binary words of length n. A Fibonacci binary word is a binary word having no 00 subword.at n=18A129720
- Number of 0's in even position in all Fibonacci binary words of length n. A Fibonacci binary word is a binary word having no 00 subword.at n=18A129722
- Positive numbers y such that y^2 is of the form x^2+(x+647)^2 with integer x.at n=6A159641
- a(n) = (4*n^3 - 6*n^2 + 8*n + 3)/3.at n=24A161712
- Number of meanders of length n.at n=14A199932
- Riordan array (1/(1-3*x+x^2), x*(1-x)/(1-3*x+x^2)).at n=46A206800
- Triangle of coefficients of polynomials u(n,x) jointly generated with A210742; see the Formula section.at n=53A210741
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-2), where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4.at n=17A293076
- Numbers k such that A163511(k) is a fifth power.at n=31A365802
- Triangular array T(n,k), read by rows: coefficients of strong divisibility sequence of polynomials p(1,x) = 1, p(2,x) = 1 + 3*x, p(n,x) = u*p(n-1,x) + v*p(n-2,x) for n >= 3, where u = p(2,x), v = 1 - x - x^2.at n=53A367208