9099
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
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13520
- Proper Divisor Sum (Aliquot Sum)
- 4421
- 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
- 6048
- Möbius Function
- 0
- Radical
- 1011
- Omega Function (Ω)
- 4
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 122
- 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
- Number of ways of n-coloring a dodecahedron.at n=2A000545
- a(n) = n*(25*n - 1)/2.at n=27A022282
- Numbers k that divide the (right) concatenation of all numbers <= k written in base 9 (most significant digit on left).at n=22A029454
- Numbers k such that k-th and (k+1)-st term of A038593 differ by 5.at n=12A038636
- Number of partitions satisfying cn(0,5) + cn(1,5) + cn(4,5) <= cn(2,5) + cn(3,5).at n=37A039878
- Numbers having three 9's in base 10.at n=9A043527
- Numbers k such that gcd(k, reverse(k)) = 27 = 3^3, where reverse(x) = A004086(x).at n=36A072016
- Representative lunar primes.at n=29A088574
- Draw a line through every pair of points with coordinates (x, 1) and (x', 2) with x, x' in 1..n, and then count the number of intersection points above the line y = 2.at n=18A092275
- Numbers whose set of base 10 digits is {0,9}.at n=11A097256
- Number of permutations of length n which avoid the patterns 1234, 2143, 3421.at n=18A116842
- (Sum of the squares of the quadratic nonresidues of prime(n)) / prime(n).at n=45A125618
- Partial sums of the generalized Cuban primes A007645.at n=42A172113
- Number of 2 X 2 matrices with all terms in {0,1,...,n} and (sum of terms) = n + 3.at n=33A210375
- Number of degree-n permutations of prime order.at n=7A214003
- Least number k such that (n!+k)/n and (n!-k)/n are both prime.at n=24A245697
- Number of length n 1..(5+1) arrays with every leading partial sum divisible by 2, 3, 5 or 7.at n=5A258628
- T(n,k)=Number of length n 1..(k+1) arrays with every leading partial sum divisible by 2, 3, 5 or 7.at n=50A258631
- Number of length 6 1..(n+1) arrays with every leading partial sum divisible by 2, 3, 5 or 7.at n=4A258637
- If n mod 3 = 0 then a(n) = 3^(n/3) + 12*n, if n mod 3 = 1 then a(n) = 4*3^((n-4)/3) + 12*n + 51, otherwise a(n) = 2*3^((n-2)/3) + 12*n - 36.at n=22A276401