8434
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12654
- Proper Divisor Sum (Aliquot Sum)
- 4220
- 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
- 4216
- Möbius Function
- 1
- Radical
- 8434
- 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
- 57
- 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
- yes
- Odd
- no
Appears in sequences
- Magic numbers: atoms with full shells containing any of these numbers of electrons are considered electronically stable.at n=34A018227
- Numbers k such that the continued fraction for sqrt(k) has period 82.at n=18A020421
- 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=22A031588
- Number of partitions of n with equal nonzero number of parts congruent to each of 1 and 3 (mod 4).at n=42A035550
- A035550 with periodic zeros stripped.at n=20A035595
- Numbers k such that numerator(Bernoulli(2*k)/(2*k)) is different from numerator(Bernoulli(2*k)/(2*k*(2*k-1))).at n=29A090495
- Number of n X 3 1..2 arrays containing at least one of each value, all equal values connected, rows considered as a single number in nondecreasing order, and columns considered as a single number in nonincreasing order.at n=34A166830
- G.f. satisfies: A(x) = 1 + (eta(x^2*A(x)^2)^10 / (eta(x*A(x))^4 * eta(x^4*A(x)^4)^4) - 1)/4, where eta(q) is the Dedekind eta function without the q^(1/24) factor.at n=10A202135
- Number of (n+1) X 4 binary arrays with consecutive windows of two bits considered as a binary number nondecreasing in every row and column.at n=13A202330
- Difference between the number of odd parts and the number of even parts in all the partitions of n.at n=26A209423
- a(n) = A122536(n) - A216958(n).at n=28A216960
- a(n) is the n-th b > 1 such that p = prime(n) satisfies b^(p-1) == 1 (mod p^2).at n=40A280721
- 4-untouchable numbers.at n=43A284156
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + n*b(n-2), where a(0) = 2, a(1) = 3, b(0) = 1, and (a(n)) and (b(n)) are increasing complementary sequences.at n=13A296287
- Number of "forceless" (or "useless") sequences in n-column Nonogram puzzle.at n=22A304179
- Coefficients of the polynomials generated by the e.g.f. cosh(x*z)*(x-1)/(x-exp(z*(x-1))), triangle read by rows, T(n,k) for 0 <= k <= n.at n=52A318143
- E.g.f.: Sum_{n>=0} 2^n * (exp(n*x) - 1)^n / n!.at n=4A326270
- Even semiprimes such that the next semiprime is also even.at n=50A328036
- Number of partitions of 2n that describe the degree sequence of exactly one labeled multigraph with no loops.at n=31A328863
- Numbers k such that usigma(uphi(k)) = uphi(usigma(k)), where usigma is the sum of unitary divisors function (A034448) and uphi is the unitary totient function (A047994).at n=29A329730