9807
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14976
- Proper Divisor Sum (Aliquot Sum)
- 5169
- 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
- 5592
- Möbius Function
- -1
- Radical
- 9807
- 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
- a(n) = Sum_{i=0..n} Sum_{j=0..n} T(i,j), T given by A026769.at n=11A026778
- T(n, 2*n-3), T given by A027960.at n=36A027965
- 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 33.at n=28A031531
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 33.at n=2A031711
- Column 2 of triangle A055907.at n=25A055908
- a(n) = (n^3 + 6n^2 - n + 12)/6.at n=37A074742
- Interprimes (A024675) which are of the form s*prime, s=21.at n=24A075296
- Number of primes of the form 30k + 1 less than 10^n.at n=5A091165
- Row sums of Riordan array A110165.at n=6A110166
- Starting numbers for which the RATS sequence has eventual period 14.at n=31A114615
- Triangle read by rows, T(n,k) = (2^k-1) * T(n-1,k) + T(n-1,k-1).at n=33A139382
- 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), (-1, 0, 0), (0, 0, -1), (1, 0, -1), (1, 1, 0)}.at n=9A148682
- Triangle T(n,k,2) read by rows (generalized q-Stirling numbers of second kind): T(n, k, q_) = (1/(q - 1)^k)*Sum[(-1)^(k - j)*q*Binomial[k + n, k -j] - Binomial[j + n, j, q - 1], {j, 0, k}], with q=2, where Binomial[,] is the Gaussian q-binomial coefficient as in A022166.at n=23A156823
- Numbers with distinct digits appearing in partition of decimal expansion of square root of 2. (A002193).at n=10A167834
- Numbers x such that 0 < |x^9 - y^8| < x^(55/8) for some number y.at n=1A173374
- Number of 0..2 arrays of length n+5 with sum less than 6 in any length 6 subsequence (=less than 50% duty cycle).at n=4A212724
- T(n,k)=Number of 0..2 arrays of length n+2*k-1 with sum less than 2*k in any length 2k subsequence (=less than 50% duty cycle).at n=25A212729
- Number of 0..2 arrays of length 2*n+4 with sum less than 2*n in any length 2n subsequence (=less than 50% duty cycle).at n=2A212734
- Number of genus 2 sensed hypermaps with n darts.at n=7A214819
- a(n) is the minimal k such that nextprime(2k+1) - 2k = prime(n) where nextprime(n) is least prime > n.at n=14A229512