8166
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 16344
- Proper Divisor Sum (Aliquot Sum)
- 8178
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 2720
- Möbius Function
- -1
- Radical
- 8166
- 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
- 65
- 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
- Second-order Eulerian numbers: a(n) = 2^n - 2*n.at n=13A005803
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = (Lucas numbers).at n=13A024858
- 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 90.at n=4A031588
- Multiplicity of highest weight (or singular) vectors associated with character chi_18 of Monster module.at n=37A034406
- Numbers whose concatenation of prime factors (with multiplicity) is a square.at n=22A038693
- Numbers k such that the number of primes <= k is phi(phi(k)).at n=17A063999
- Values of m such that N = (am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,3.at n=37A064238
- Numbers m such that N = (am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,55.at n=2A065696
- pi(n) is a power of 2, where pi(n) = A000720(n) is the number of primes <= n.at n=42A073798
- Expansion of (1-x)^(-1)/(1 - x - 2*x^2 + 2*x^3).at n=21A077866
- Expansion of 1/(1+2*x+2*x^2-x^3).at n=19A077992
- a(n) = A078152(2^n).at n=23A078157
- Revrepfigits (reverse replicating Fibonacci-like digits): Numbers k whose reversal occurs in a sequence generated by starting with the k digits of a number and then continuing the sequence with a number that is the sum of the previous k terms.at n=10A097060
- Records in A101119, which forms the nonzero differences of A006519 and A003484.at n=9A101120
- Triangle T(n,k) (n >= 1, 0 <= k <= floor((n-1)/2)) read by rows, where T(n,k) = (k+1)T(n-1,k) + (2n-4k)T(n-1,k-1).at n=43A101280
- Numbers k such that k^2 + 11 and k^2 + 13 are primes.at n=34A113537
- Algebraic degree of the onset of the logistic map n-bifurcation.at n=12A118454
- Sequence S with property that for n in S, a(n) = a(1) + a(2) +...+ a(n-1) and for n not in S, a(n) = n+1.at n=21A121173
- Sequence S with the following properties: (i) a(1)=2; (ii) for n in S, a(n)=a(1)+a(2)+...+a(n-1); (iii) for n not in S, a(n)=the smallest number different from a(1), ..., a(n-1) not breaking property (ii).at n=21A121175
- Numbers n such that n^3 is zeroless pandigital.at n=37A124628