9789
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 33
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14112
- Proper Divisor Sum (Aliquot Sum)
- 4323
- 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
- 6000
- Möbius Function
- -1
- Radical
- 9789
- 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
- no
- Odd
- yes
Appears in sequences
- Length of one version of Kolakoski sequence {A000002(i)} at n-th growth stage.at n=23A001083
- List of pairs of primes in reverse order, starting at 1.at n=12A007796
- Expansion of g.f. 1/((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 8*x)).at n=4A021044
- a(n) = n*(29*n - 1)/2.at n=26A022286
- First partial sums of A005409; second partial sums of A001333.at n=9A048777
- a(n) is the smallest number k such that k! contains k exactly n times.at n=11A061014
- a(n) = A077696(n+1)/A077696(n).at n=11A077697
- a(1)=1, a(n+1)=ceiling(phi*a(n))+1 if a(n) is odd, a(n+1)=ceiling(phi*a(n)) if a(n) is even, where phi=(1+sqrt(5))/2.at n=17A092263
- a(n) = number of Egyptian fractions 1 = 1/x_1 + ... + 1/x_k (for any k), with 0 < x_1 <= ... <= x_k = n.at n=24A092666
- Starting numbers for which the RATS sequence has eventual period 14.at n=30A114615
- a(1)=1, a(n) = a(n-1) + n^4 if n odd, a(n) = a(n-1) + n^2 if n is even.at n=8A140159
- a(n) = prime(n) * prime(n+2) - 2 * prime(n+1).at n=24A152532
- Row sums of triangle T(j,k) = (j^k) mod (j*k) for 1 <= k <= j (see A096133).at n=38A157351
- Number of n X 10 binary arrays with all 1s connected and a path of 1s from top row to lower right corner.at n=1A163019
- Number of permutations of order n avoiding the consecutive pattern 11'2'2.at n=8A177472
- Numbers with rounded up arithmetic mean of digits = 9.at n=30A178369
- Parameters k for which the Tate-Shafarevich group Ш of the elliptic curve y^2=x^3-k has order 25.at n=9A179139
- T(n,k)=Number of (n+1)X(k+1) 0..7 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors.at n=7A186490
- T(n,k)=Number of (n+1)X(k+1) 0..7 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors.at n=8A186490
- T(n,m)=Number of (n+1)X4 0..m arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors.at n=29A188058