17185
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 23616
- Proper Divisor Sum (Aliquot Sum)
- 6431
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11760
- Möbius Function
- -1
- Radical
- 17185
- Omega Function (Ω)
- 3
- 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
- 79
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- a(1)=1, a(n) = n*16^(n-1) + a(n-1).at n=3A014931
- Least nonsquare having square residues for all moduli 2 through n.at n=21A018883
- Least nonsquare having square residues for all moduli 2 through n.at n=22A018883
- Numbers whose base-7 representation has exactly 6 runs.at n=24A043621
- Number of reversible string structures with n beads using exactly four different colors.at n=9A056328
- a(n) = 1 + 2*n + 3*n^2 + 4*n^3.at n=16A056578
- a(n) = (1/6)*n^5 - (19/8)*n^4 + (51/4)*n^3 - (253/8)*n^2 + (445/12)*n - 14.at n=12A059999
- Numbers with ever-increasing minimal-square-deniers.at n=11A066730
- Triangular matrix T, read by rows, that satisfies: SHIFT_LEFT(column 0 of T^p) = p*(column p+1 of T), or [T^p](m,0) = p*T(p+m,p+1) for all m>=1 and p>=-1.at n=49A104980
- a(0)=1. a(n) = sum{k=0 to n-1} a(a(k)(mod n)).at n=22A125952
- a(n) = Number of x <= 10^n such that 2x^2-1 is prime.at n=4A143835
- Riordan array [exp(-x/2)(1-2x)^(-1/4),x].at n=29A152148
- Triangle read by rows: T(n,k) = number of reversible string structures of length n using exactly k different symbols.at n=48A284949
- Number of Motzkin trees that are "untypable closable skeletons".at n=14A300129
- Number of 6-cycles in the (n+5)-path complement graph.at n=7A302695
- Irregular triangle: T(n,k) is the number of permutations in S_n that have exactly k occurrences of the pattern 4213. 0 <= k <= A342646(n).at n=61A342840
- Expansion of e.g.f. exp(exp(4*x) - 1 - 3*x).at n=5A367940