6881
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7872
- Proper Divisor Sum (Aliquot Sum)
- 991
- 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
- 5892
- Möbius Function
- 1
- Radical
- 6881
- 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
- 119
- 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 the continued fraction for sqrt(k) has period 76.at n=11A020415
- Numbers k such that Fib(k) == -13 (mod k).at n=27A023167
- Numbers k such that if d,e are consecutive digits of k in base 6, then |d-e| >= 4.at n=43A032988
- Sizes of successive clusters in Z^4 lattice.at n=37A046895
- Composite numbers not ending in zero that yield a prime when turned upside down.at n=42A048889
- Number of 3 X n binary matrices with no zero rows or columns, up to row and column permutation.at n=13A055609
- Partial sums of A068058 + 1.at n=35A068059
- Numbers n such that [A070080(n), A070081(n), A070082(n)] is an isosceles integer triangle with integer area.at n=18A070145
- Numbers k such that [A070080(k), A070081(k), A070082(k)] is an obtuse integer triangle with integer area.at n=34A070147
- Numbers k such that the k-th semiprime == 11 (mod k).at n=8A106136
- Number of partitions that are "2-close" to being self-conjugate.at n=43A108961
- Number of symmetric n X n (0,1)-matrices over the reals with zero permanent.at n=4A118989
- an=n-th smallest integer of the form m=p1*p2 where pi are odd primes such that d+2m/d are all primes for d dividing 2m.at n=44A128279
- Number of Section I primes between 2^n and 2^(n+1). See A135832.at n=36A135833
- 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, 0), (0, 0, -1), (0, 0, 1), (0, 1, -1), (1, 0, 1)}.at n=7A150670
- a(n) = (2*n^3 + 9*n^2 + n + 24) / 6.at n=26A160805
- a(n) = 4*n^2 + 4*n - 7.at n=40A166147
- Positive integers of the form (10*m^2+1)/11.at n=15A179338
- Number of strings of numbers x(i=1..6) in 0..n with sum i*x(i)^3 equal to 6*n^3.at n=35A184723
- Numbers of the form (4k+3)^2-8 or (4k+5)^2+4.at n=40A214405