9128
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 19680
- Proper Divisor Sum (Aliquot Sum)
- 10552
- 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
- 3888
- Möbius Function
- 0
- Radical
- 2282
- Omega Function (Ω)
- 5
- 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
- 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
- a(n) = 6*n^2 + 2 for n > 0, a(0)=1.at n=39A005897
- Coordination sequence for NiAs(1), As position.at n=39A009943
- a(n) = Sum_{k=1..n} ceiling(k^4/n).at n=13A014816
- Expansion of (theta_3(z)*theta_3(2z)+theta_2(z)*theta_2(2z))^4.at n=36A028579
- a(n) is the smallest k > a(n-1) such that k^2 has no digit in common with a(n-1)^2.at n=42A030287
- Trajectory of 3 under map n->15n+1 if n odd, n->n/2 if n even.at n=13A037105
- Gaps of 8 in sequence A038593 (lower terms).at n=8A038655
- Numbers ending with '8' that are the difference of two positive cubes.at n=32A038863
- Numerators of continued fraction convergents to sqrt(417).at n=7A041792
- a(n) = n*(n+1)*(n+2)*(n^2+7*n+32)/120.at n=13A051747
- Numbers n such that r(k) * 2^n + 1 is prime, where r() = A002275 the repunits and k is the number of decimal digits of 2^n.at n=15A095306
- Number of triangles in an n X n grid of squares with diagonals.at n=14A100583
- Even numbers n such that n^2 is an arithmetic number.at n=40A107924
- Numbers k such that digit sum of 3^k is a power of 3.at n=27A118872
- a(n) = tau(n) * (NumberOfPartitions(n) - 1).at n=29A141668
- a(n) = 2*n*A071148(n).at n=13A177082
- a(1) = 2, a(n) = (n-th-even n^3) - (sum of previous terms).at n=20A181509
- Number of right triangles on a (n+1)X8 grid.at n=8A189812
- (A192533)/2.at n=21A192534
- Number of n X n 0..7 arrays with row and column sums one greater than the previous row and column.at n=2A202863