17717
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 20256
- Proper Divisor Sum (Aliquot Sum)
- 2539
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15180
- Möbius Function
- 1
- Radical
- 17717
- 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
- no
- 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
- G.f.: (1 + x^4 + x^7 + 2*x^8 + x^9 + x^12 + x^16)/Product_{i=1..8} (1 - x^i).at n=36A003405
- Number of ways to cover (without overlapping) a ring lattice (necklace) of n sites with molecules that are 7 sites wide.at n=42A058366
- Average of terms in n-th row of A077529.at n=22A077532
- One fifth of the sum of the first n primes, when an integer.at n=29A112271
- Define the first two terms to be 1 and 7. All the other terms are obtained by concatenating the two previous terms.at n=4A113765
- a(n) = (n-1)*a(n-1) - a(n-4) with a(0)=0, a(1)=1, a(2)=2, a(3)=1.at n=9A122050
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 1, -1), (1, -1, 0), (1, 0, -1), (1, 1, 1)}.at n=8A149597
- a(n) = Least i in range [A165598(n),A165598(n+1)] for which abs(A165597(i)) gets the maximum value in that range.at n=9A165599
- Number of toothpicks after n stages of 3-D toothpick structure defined in Comments.at n=29A170876
- Number of nontrivial compositions of differential operations and directional derivative of the n-th order on the space R^10.at n=21A187179
- Number of 3 X n 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4.at n=18A240395
- Number of (n+1) X (5+1) 0..1 arrays with no 2 X 2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements.at n=12A251125
- Numbers using only digits 1 and 7.at n=43A276039
- p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - S^4.at n=23A291379
- a(n) = Sum_{k=0..floor(n/8)} binomial(n-4*k,4*k).at n=24A348289
- Numbers k such that A361338(k) = 9.at n=34A361348