8108
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 14196
- Proper Divisor Sum (Aliquot Sum)
- 6088
- 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
- 4052
- Möbius Function
- 0
- Radical
- 4054
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 158
- 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
- Numbers that, when expressed in base 7 and then interpreted in base 10, yield a multiple of the original number.at n=24A032549
- Number of partitions satisfying (cn(1,5) <= cn(2,5) and cn(1,5) <= cn(3,5) and cn(4,5) <= cn(2,5) and cn(4,5) <= cn(3,5)).at n=42A036803
- Numerators of continued fraction convergents to sqrt(161).at n=8A041296
- At stage 1, start with a unit square. At each successive stage add 4*(n-1) new squares around outside with edge-to-edge contacts. Sequence gives number of squares (regardless of size) at n-th stage.at n=22A056640
- Numbers k that, when expressed in base 7 and then interpreted in base 10, give a multiple of k.at n=25A062944
- Numbers n whose sum of divisors and number of divisors are both triangular numbers.at n=26A070996
- Fundamental discriminants of real quadratic number fields with class number 5.at n=37A094614
- Indices of squares (of primes) in the semiprimes.at n=41A128301
- Numbers k such that 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*p(k+5)-1 and 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*p(k+5)+1 are twin primes with p(h) = h-th prime.at n=12A129311
- Expansion of g.f.: 1/(1 - x - 2*x^2 + x^3 + x^4 + 2*x^7 - 5*x^9 + 2*x^11 + x^14 + x^15 - 2*x^16 - x^17 + x^18).at n=19A147622
- 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, 1), (-1, 0, 0), (0, 1, 0), (1, -1, -1), (1, 1, 1)}.at n=7A150516
- Number of 3-step self-avoiding walks on an n X n square summed over all starting positions.at n=26A188148
- a(n) = a(n-1) + a(n-2) + n + 3 with n>1, a(0)=1, a(1)=2.at n=15A210729
- Walks of length n on the x-axis using steps {1,-1} and visiting no point more than twice.at n=23A212585
- Number of conjugacy classes in Chevalley group G_2(q) as q runs through the prime powers.at n=33A225929
- Numbers k such that sigma(tau(phi(k))) = phi(tau(sigma(k))).at n=35A226118
- Number of partitions of n whose median is not a part.at n=40A238479
- Number of n-node unlabeled rooted trees with thinning limbs and root outdegree (branching factor) 5.at n=12A244706
- a(0) = 16, after which, if a(n-1) = product_{k >= 1} (p_k)^(c_k), then a(n) = (1/2) * (1 + product_{k >= 1} (p_{k+1})^(c_k)), where p_k indicates the k-th prime, A000040(k).at n=25A246344
- a(n) = phi(2^n) - phi(n^2), with Euler's totient function phi = A000010.at n=13A248643