6559
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7504
- Proper Divisor Sum (Aliquot Sum)
- 945
- 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
- 5616
- Möbius Function
- 1
- Radical
- 6559
- 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
- 49
- 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
- Numbers k such that (1,k) is "good".at n=38A000696
- Erroneous version of A348211.at n=24A013561
- Ordered sequence of distinct terms of the form floor(x^i * floor(x^j)), i,j >= 0, where x = sqrt(3).at n=45A022769
- Numbers k such that Fib(k) == -13 (mod k).at n=24A023167
- 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 79.at n=32A031577
- Numbers having three 8's in base 9.at n=31A043487
- Numbers whose base-3 representation contains no 0's and exactly one 1.at n=35A044966
- a(n) = 3^n - 2.at n=7A058481
- Square array T(k,n) by antidiagonals, where T(k,n) is number of ways of placing n identifiable nonnegative intervals with a total of exactly k starting and/or finishing points.at n=63A059515
- a(n) = 4*n^2 + 4*n - 1.at n=39A073577
- Numbers k such that k^5 + 4^k is prime.at n=7A075982
- Greatest squarefree number not exceeding n-th prime power which is not prime.at n=46A081218
- Sum of n-th antidiagonal of A082191.at n=21A082195
- a(n) = 2*a(n-1) + (-1)^n*a(floor(n/2)); a(1)=1.at n=12A089067
- Number of Motzkin paths of length n with no UD, UHD, UHHD, UHHHD, ..., starting at level zero (here H=(1,0), U=(1,1), D=(1,-1)).at n=12A089380
- Where A093316 first equals n.at n=18A093319
- Triangle read by rows: T(n,k) is the number of Motzkin paths of length n having k low humps. (A hump is an upstep followed by 0 or more flatsteps followed by a downstep. A low hump is a hump that starts at level zero.).at n=42A097887
- A bisection of A000960.at n=45A099061
- a(n) = (2^n + 1)^4 - 2.at n=3A099360
- Number of partitions of n having positive odd rank (the rank of a partition is the largest part minus the number of parts).at n=38A101707