9120
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 48
- Divisor Sum
- 30240
- Proper Divisor Sum (Aliquot Sum)
- 21120
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2304
- Möbius Function
- 0
- Radical
- 570
- Omega Function (Ω)
- 8
- Little Omega Function (ω)
- 4
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
- yes
Recreational
- Happy Number
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 109
- 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
- yes
- Odd
- no
Appears in sequences
- Coordination sequence for E_8 lattice.at n=2A008340
- Theta series of D*_20 lattice.at n=3A022073
- a(n) = (-1 + prime(n+1)^2)/4.at n=41A024701
- a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-3)*a(3) for n >= 4, with initial terms 3, -2, 1, 3.at n=11A025261
- Theta series of 6-dimensional lattice of det 8.at n=37A029543
- Longest edge a of smallest (measured by the longest edge) primitive Euler bricks (a, b, c, sqrt(a^2 + b^2), sqrt(b^2 + c^2), sqrt(a^2 + c^2) are integers).at n=17A031173
- Number of points of l_1 norm n in the "diamond" lattice D^+_4.at n=19A035878
- Numbers that divide the sum of cubes of their divisors.at n=32A046763
- a(n) = a(n-3) + a(n-5) with initial values 1,0,0,1,0.at n=59A052920
- Number of connected unlabeled digraphs with n nodes such that complement is also connected.at n=4A054918
- Triangle read by rows: this is a variant of A008280 in which 2 rows go from left to right, 2 from right to left, 2 from left to right, etc.at n=64A058257
- Number of solutions to x + y + z = 0 mod (2n+1) such that x,y,z are units modulo 2n+1, i.e., gcd(x, 2n+1) = gcd(y, 2n+1) = gcd(z, 2n+1) = 1.at n=47A061780
- Numbers k such that sigma(k) - usigma(k) is a square and sets a new record for such squares.at n=20A063840
- Numbers k such that sigma(k) divides sigma(sigma(k)).at n=16A066961
- a(n) = 6*n^2 + 12*n.at n=37A067726
- Numbers k such that phi(k) = tau(k)^2.at n=26A068560
- First differences of A069474, successive differences of (n+1)^6-n^6.at n=3A069475
- Numbers k such that sigma(k) is a harmonic number.at n=33A074245
- Largest possible z-value of an integer solution (x,y,z) to 4/n = 1/x + 1/y + 1/z satisfying 0 < x < y < z. The x and y components are in A075245 and A075246.at n=16A075247
- Omega(n) = Omega(n-1)^3, where Omega(m) (A001222) denotes the number of prime factors of m, counting multiplicity.at n=40A076155