9878
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 32
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 16200
- Proper Divisor Sum (Aliquot Sum)
- 6322
- 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
- 4480
- Möbius Function
- -1
- Radical
- 9878
- 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
- 135
- 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
- A Fielder sequence.at n=16A001640
- Number of paraffins.at n=34A005999
- Integer part of Sum_{i=1..n} binomial(n,i) * (n/i)^i.at n=8A007806
- Magic numbers: atoms with full shells containing any of these numbers of electrons are considered electronically stable.at n=36A018227
- a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t = A002808 (composite numbers).at n=41A023863
- n written in fractional base 10/9.at n=38A024664
- 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 = (composite numbers).at n=40A024860
- 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 98.at n=18A031596
- Numbers whose base-4 representation contains exactly three 1's and four 2's.at n=22A045104
- Let v = (1,4,9,...,n^2), x = (0,1,2,4,6,...) [first n terms of A002620]; a(n) = v.v * x.x - (v.x)^2.at n=10A060452
- Consider the line segment in R^n from the origin to the point v = (1,4,9,...,n^2); let d = squared distance to this line from the closest point of Z^n (excluding the endpoints). Sequence gives d times v.v.at n=9A060454
- Sum of digits = 8 times number of digits.at n=41A061425
- (10^n)-th zero of the Riemann zeta function rounded to the nearest integer.at n=4A082668
- Column 4 of an array closely related to A083480. (Both arrays have shape sequence A083479).at n=9A089574
- Triangle (read by rows) formed by setting all entries in the first column and in the main diagonal ((i,i) entries) to 1 and the rest of the entries by the recursion T(n, k) = T(n-1, k) + T(n, k-1).at n=73A096465
- Triangle read by rows: T(n,k) is number of Dyck paths of semilength n and having leftmost valley at altitude k (if path has no valleys, then this altitude is considered to be 0).at n=49A097607
- Expansion of 2*(2*x+1)/((x+1)*(sqrt(4*x+1)+1)).at n=10A104496
- Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having length of second ascent equal to k (0<=k<=n-1).at n=58A114276
- Sum of the lengths of the second ascents in all Dyck paths of semilength n+2.at n=7A114277
- Number of ordered quadruples (i,j,k,l) in range [0..n] satisfying i == j (mod 2), j == k (mod 3) and k == l (mod 4).at n=21A115523