9819
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 14196
- Proper Divisor Sum (Aliquot Sum)
- 4377
- 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
- 6540
- Möbius Function
- 0
- Radical
- 3273
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 73
- 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
- no
- Odd
- yes
Appears in sequences
- Molien series for alternating group Alt_8 (or A_8).at n=40A008631
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite NES = NU-87 H4[Al4Si64O136].nH2O starting with a T3 atom.at n=12A019204
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 11.at n=8A031689
- For each prime p take the sum of nonprimes < p.at n=36A045717
- Composite numbers k for which phi(k) + sigma(k) is an integer multiple of the 4th power of the number of divisors of k.at n=38A055468
- Numbers n whose sum of divisors and number of divisors are both triangular numbers.at n=31A070996
- Consider the family of multigraphs enriched by the species of binary arborescences. Sequence gives number of those multigraphs with n loops and arcs.at n=4A098344
- sigma(n) + phi(n) is a fourth power.at n=5A114068
- Number of partitions of n into parts which are not digits of n in decimal representation.at n=48A136460
- 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), (0, 1, -1), (1, 0, 1), (1, 1, -1)}.at n=9A148721
- Partial sums of A004123.at n=5A174278
- a(n) = 121*n^2 + 2*n.at n=8A181679
- Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..7 array extended with zeros and convolved with 1,2,2,1.at n=19A222110
- Number of (n+1)X(2+1) 0..2 arrays x(i,j) with row sums sum{j^3*x(i,j), j=1..2+1} nondecreasing, and column sums sum{i^3*x(i,j), i=1..n+1} nondecreasing.at n=2A232785
- Number of (n+1)X(3+1) 0..2 arrays x(i,j) with row sums sum{j^3*x(i,j), j=1..3+1} nondecreasing, and column sums sum{i^3*x(i,j), i=1..n+1} nondecreasing.at n=1A232786
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays x(i,j) with row sums sum{j^3*x(i,j), j=1..k+1} nondecreasing, and column sums sum{i^3*x(i,j), i=1..n+1} nondecreasing.at n=7A232787
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays x(i,j) with row sums sum{j^3*x(i,j), j=1..k+1} nondecreasing, and column sums sum{i^3*x(i,j), i=1..n+1} nondecreasing.at n=8A232787
- Numbers n such that floor( n^(3/2) ) is a concatenation of two successive numbers.at n=11A244289
- The number phi_5(n) of Frobenius partitions that allow up to 5 repetitions of an integer in a row.at n=20A247662
- a(n) = 4*n^2 - 4*n + 19, n >= 1.at n=49A259054