8906
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
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13764
- Proper Divisor Sum (Aliquot Sum)
- 4858
- 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
- 4320
- Möbius Function
- -1
- Radical
- 8906
- 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
- 140
- 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
- yes
- Odd
- no
Appears in sequences
- The sequence m(n) in A022905.at n=44A022907
- Base-8 palindromes that start with 2.at n=29A043022
- a(n) = a(n-2) + a(n-3), with a(0) = 3, a(1) = 2, a(2) = 6.at n=29A046877
- Number of basis partitions of n+16 with Durfee square size 4.at n=43A053798
- a(n) = Sum of all numbers of divisors of all numbers < (n+1)^2.at n=33A168011
- Constant term of the reduction by x^2 -> x+1 of the polynomial p(n,x) defined at Comments.at n=14A192973
- Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of the matrix at A204112, given by f(i,j) = gcd(F(i+1), F(j+1)), where F=A000045 (Fibonacci numbers).at n=31A204113
- Number of n-bead necklaces labeled with numbers -1..1 not allowing reversal, with sum zero and avoiding the pattern z z+1 z+2.at n=12A209066
- Number of partial matchings of n elements treatable by "PTR" (Procedure Triple Reverse).at n=10A220871
- Sum of the first n strobogrammatic numbers.at n=19A230833
- Least number k not divisible by 10 such that the decimal expansion of k^n contains some digit exactly n times.at n=20A243151
- Number of (n+2) X (7+2) 0..1 arrays with no 3 X 3 subblock diagonal sum 0 and no antidiagonal sum 3 and no row sum 0 or 3 and no column sum 0 or 3.at n=15A258965
- Solutions to phi(n) = phi(sigma(n)) that are not given by Theorem 3 of Golomb's manuscript.at n=52A260021
- Least number x such that x^n has n digits equal to k. Case k = 6.at n=20A285453
- Approximation of the 2-adic integer arctan(2) up to 2^n.at n=14A309751
- Even numbers k such that A156552(k) is not a power of prime, and for which A323243(k) = sigma(A156552(k)) is congruent to 2 modulo 8.at n=29A332229
- a(n) = Sum_{d|n} d^phi(n/d).at n=47A344484
- a(n) is the smallest number which can be represented as the sum of n distinct nonzero squares in exactly n ways, or 0 if no such number exists.at n=27A350241
- Triangle read by rows: T(n, k) = n! * 4^k * hypergeom([-k], [-n], 1/4).at n=18A375613