2556
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 6552
- Proper Divisor Sum (Aliquot Sum)
- 3996
- 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
- 840
- Möbius Function
- 0
- Radical
- 426
- 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
- yes
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- yes
- 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
- 133
- Smith Number
- yes
- 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
- Dying rabbits: a(0) = 1; for 1 <= n <= 12, a(n) = Fibonacci(n); for n >= 13, a(n) = a(n-1) + a(n-2) - a(n-13).at n=18A000044
- Hexagonal numbers: a(n) = n*(2*n-1).at n=36A000384
- a(n) = n^2*(2*n^2 - 1); also Sum_{k=0..n-1} (2k+1)^3.at n=6A002593
- Binomial coefficient C(6n,n-10).at n=2A004365
- Binomial coefficient C(8n,n-7).at n=2A004388
- Number of Young tableaux of height <= 6.at n=9A007579
- Distinct perimeter lengths of polygons with regularly spaced vertices.at n=11A007874
- Coordination sequence T5 for Zeolite Code AET.at n=35A008011
- Coordination sequence T1 for Zeolite Code APC.at n=35A008032
- Coordination sequence T2 for Coesite.at n=27A008268
- Theta series of direct sum of 2 copies of f.c.c. lattice.at n=8A008663
- a(n) = prime(n)*(prime(n+1)-1)/2.at n=19A014303
- Even triangular numbers.at n=35A014494
- a(n) = 2*n*(4*n - 1).at n=18A014635
- Binomial coefficients C(n,70).at n=2A017734
- Binomial coefficients C(72,n).at n=2A017788
- Expansion of 1/(1-x^8-x^9-x^10-x^11-x^12-x^13-x^14-x^15).at n=54A017873
- Pseudoprimes to base 37.at n=41A020165
- Pseudoprimes to base 73.at n=38A020201
- Sequence satisfies T^2(a)=a, where T is defined below.at n=47A027587