6508
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 11396
- Proper Divisor Sum (Aliquot Sum)
- 4888
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3252
- Möbius Function
- 0
- Radical
- 3254
- Omega Function (Ω)
- 3
- 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
- 75
- 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
- yes
- Odd
- no
Appears in sequences
- Expansion of e.g.f. arctanh(exp(x)*log(x+1)).at n=7A012278
- [ (4th elementary symmetric function of S(n))/(2nd elementary symmetric of S(n)) ], where S(n) = {3,4, ..., n+5}.at n=19A024194
- a(n) = ( 1/1 + 1/3 + 1/5 + ... + 1/(2*n-1) )*LCM(1, 3, 5, ..., 2*n-1).at n=5A025550
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 40.at n=41A031538
- Numerators of alternating sum transform (PSumSIGN) of Harmonic numbers H(n) = A001008/A002805.at n=10A035048
- Number of partitions of n into parts not of the form 19k, 19k+6 or 19k-6. Also number of partitions with at most 5 parts of size 1 and differences between parts at distance 8 are greater than 1.at n=32A035975
- Numbers n such that there are equal numbers of 0's and 1's in first n digits of binary representation of Pi.at n=24A039624
- T(n,4), array T as in A054126.at n=6A054130
- Numbers k such that k^256 + 1 is prime.at n=20A056995
- a(n) = Sum_{d|n} d^2*2^(d-1)*(n/d-1) for n > 0.at n=21A077272
- 1 + sum of first n 4-almost primes.at n=40A110226
- Number of partitions of n which represent losing Chomp positions.at n=52A112470
- Integer part of Gauss's Arithmetic-Geometric Mean M(1,n^4).at n=14A127760
- Array read by antidiagonals: T(n,k) is the number of n-step king's tours on a k X k board summed over all starting positions.at n=39A186861
- Number of 4-step king's tours on an n X n board summed over all starting positions.at n=5A186863
- a(n) = A188493(n+1) - A188491(n) - A188495(n).at n=10A188497
- Number of ways to place n nonattacking composite pieces rook + rider[1,2] on an n X n chessboard.at n=10A189837
- Numbers k such that (k+1)^(k-1) - k is prime.at n=11A240532
- Triangle read by rows: T(n,k) is the coefficient A_k in the transformation of 1 + x + x^2 + ... + x^n to the polynomial A_k*(x+3k)^k for 0 <= k <= n.at n=33A248977
- T(n,k)=Number of nXk integer arrays with each element equal to the number of horizontal and antidiagonal neighbors exactly one smaller than itself.at n=46A266101