9831
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13680
- Proper Divisor Sum (Aliquot Sum)
- 3849
- 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
- 6272
- Möbius Function
- -1
- Radical
- 9831
- 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
- 104
- 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
- no
- Odd
- yes
Appears in sequences
- Divisors of 2^28 - 1.at n=27A003536
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly nine 1's.at n=31A020445
- In A015922, not in A033553.at n=23A033554
- Sums of 7 distinct powers of 3.at n=34A038469
- Number of partitions satisfying cn(2,5) + cn(3,5) <= cn(1,5) + cn(4,5).at n=34A039895
- Smallest value of x such that M(x) = -n, where M(x) is Mertens's function A002321.at n=39A051401
- Inverse Mertens function: smallest k such that |M(k)| = n, where M(x) is Mertens's function A002321.at n=39A051402
- McKay-Thompson series of class 38a for Monster.at n=43A058658
- 2-boustrophedon transform (see A059294) of 0, 1, 0, 0, 0, ...at n=7A059296
- An inverse to Mertens's function: smallest k >= 2 such that Mertens's function |M(k)| (see A002321) is equal to n.at n=40A060434
- Expansion of (1-x)^(-1)/(1-x+2*x^3).at n=26A077870
- Cycle lengths in a certain class of one-dimensional cellular automata.at n=26A085596
- a(n) = a(n-1) + a(n-2) + a(n-3); a(0) = -1, a(1) = 2, a(2) = 2.at n=16A100683
- a(n) = (10^k - n)(10^k + n), where k is the number of digits in n.at n=12A110397
- a(n) = a(n-1) + 2^(k(n)), where k(n) is the n-th term of the sequence formed by k(1)=0 together with the numbers A042963.at n=7A113870
- Numbers k such that A003313(k) = A003313(5*k).at n=2A116460
- Inverse binomial transform of 1, 2, 2, 4, 10, 20, ... = A100088.at n=27A137470
- One-third of the number of n X n nonnegative integer arrays with every 3 X 3 subblock summing to 2.at n=7A145053
- 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, 0), (-1, 0, -1), (0, 1, 1), (1, -1, -1), (1, -1, 1)}.at n=9A148655
- 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, 0), (-1, 1, -1), (0, 1, 1), (1, -1, -1), (1, 1, -1)}.at n=9A148656