6840
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
- 1
Divisibility
- Divisor Count
- 48
- Divisor Sum
- 23400
- Proper Divisor Sum (Aliquot Sum)
- 16560
- 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
- 1728
- Möbius Function
- 0
- Radical
- 570
- Omega Function (Ω)
- 7
- 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
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 57
- 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
- Order of the group SL(2,Z_n).at n=18A000056
- Number of n-step polygons on hexagonal lattice.at n=9A001335
- Number of ways in which n identical balls can be distributed among 4 boxes in a row such that each pair of adjacent boxes contains at least 4 balls.at n=26A005337
- Left diagonal of partition triangle A047812.at n=29A007042
- a(n) = n*(n-1)*(n-2) (or n!/(n-3)!).at n=20A007531
- [ n(n-1)(n-2)(n-3)/17 ].at n=20A011927
- a(n) = floor(n*(n-1)*(n-2)*(n-3)/21).at n=21A011931
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly seven 1's.at n=33A020443
- Theta series of A*_19 lattice.at n=59A023931
- Cube of the lower triangular normalized Eulerian number matrix.at n=26A027538
- Second diagonal of A027538.at n=5A027542
- Records for sum of proper divisors function A001065.at n=50A034091
- Numerators of continued fraction convergents to sqrt(568).at n=5A042088
- A049031/2.at n=24A049032
- Smallest area of a Pythagorean triangle with n as length of one of the three sides.at n=35A054435
- Smallest area of a Pythagorean triangle with n as length of a leg.at n=35A054436
- Largest area of a Pythagorean triangle with n as length of one of the three sides (in fact as a leg).at n=35A055522
- a(n) = 4 * A073120(n).at n=29A057102
- Triangle of congrua: T(n,k) = 4*n*k(n^2-k^2) with n>k>0 and starting at T(2,1) = 24. A055096(n)^2 + a(n) is a square, as is A055096(n)^2 - a(n).at n=44A057103
- Coefficient triangle of polynomials (falling powers) related to Fibonacci convolutions. Companion triangle to A057282.at n=9A057281