8456
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
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 18240
- Proper Divisor Sum (Aliquot Sum)
- 9784
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3600
- Möbius Function
- 0
- Radical
- 2114
- Omega Function (Ω)
- 5
- 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
- 83
- 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
- Theta series of {D_7}* lattice.at n=52A008423
- Number of ways of writing n as a sum of 7 squares.at n=13A008451
- Expansion of e.g.f.: log(1+sinh(x)/cos(x)).at n=7A009361
- [ n(n-1)(n-2)(n-3)/11 ].at n=19A011921
- arctanh(sec(x)*sinh(x))=x+6/3!*x^3+140/5!*x^5+8456/7!*x^7...at n=3A012818
- Expansion of e.g.f. log(sinh(x) + cos(x)).at n=7A013068
- Positive integers n such that 2^n == 2^11 (mod n).at n=76A015935
- 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 21.at n=44A031519
- Triangle read by rows: T(n,k)=A(n,k)*binomial(n+k-1,n), where A(n,k) are the Eulerian numbers (A008292).at n=17A038675
- Number of nonempty subsets of {1,2,...,n} in which exactly 2/3 of the elements are <= n/3.at n=22A047195
- Number of nonempty subsets of {1,2,...,n} in which exactly 2/3 of the elements are <= (n-1)/3.at n=22A048007
- Number of nonempty subsets of {1,2,...,n} in which exactly 2/3 of the elements are <= (n-2)/3.at n=22A048018
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the unique value such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 3.at n=35A050032
- a(n) = a(n-1) + a(m) for n >= 3, where m = 2*n - 3 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = 2.at n=35A050048
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = a(3) = 3.at n=35A050064
- Numbers k such that pi(k) divides k.at n=32A057809
- Consider the sequence {b(m)} of nonprimes; sequence gives values of m where gcd{m, b(m)} increases.at n=32A058011
- Triangle T(n,k) (n >= 2, k = 3..n+floor(n/2)) giving number of bicoverings of an n-set with k blocks.at n=25A059443
- Number of 9-block bicoverings of an n-set.at n=6A059950
- Erroneous version of A134915.at n=8A076884