6660
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
- 36
- Divisor Sum
- 20748
- Proper Divisor Sum (Aliquot Sum)
- 14088
- 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
- 1110
- Omega Function (Ω)
- 6
- 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
- 181
- 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
- Number of strong starters in cyclic group of order 2n+1.at n=9A001443
- Number of partitions of floor(5n/2) into n nonnegative integers each no more than 5.at n=31A001975
- a(n) = floor(n*(n-1)*(n-2)/7).at n=37A011889
- a(n) = n^2*(n^2 + 1)*(n-1).at n=6A037250
- Positive numbers having the same set of digits in base 4 and base 9.at n=27A037427
- Base 5 digits are, in order, the first n terms of the periodic sequence with initial period 2,0,3,1.at n=5A037724
- Denominators of continued fraction convergents to sqrt(852).at n=7A042645
- a(n) = A033001(n)/4.at n=32A043307
- Numbers having three 6's in base 10.at n=18A043515
- Numbers whose base-9 representation has exactly 5 runs.at n=8A043634
- Beastly (or hateful) numbers: numbers containing the string 666 in their decimal expansion.at n=6A051003
- a(n) = Sum_{d|4} phi(d)*n^(4/d).at n=9A054603
- a(n) = Sum_{d|n} phi(d)*9^(n/d).at n=4A054616
- Triangle T(n,k) = Sum_{d|k} phi(d)*n^(k/d).at n=39A054619
- Numbers n such that phi(n) + 1 | sigma(n).at n=11A056097
- Numbers k such that sigma(x) = k has exactly 6 solutions.at n=30A060662
- Numbers k such that phi(x) = k has exactly 7 solutions.at n=40A060670
- Smallest multiple k*n of n which has even digits and is a palindrome or becomes a palindrome when 0's are added on the left (e.g., 10 becomes 010, which is a palindrome).at n=45A062293
- a(n) is the number of pairs of integer quadruples (b_1, b_2, b_3, b_4) and (c_1, c_2, c_3, c_4) satisfying 1 <= b_1 < b_2 < b_3 < b_4 < n, 1 <= c_1 < c_2 < c_3 < c_4 < n, b_i != c_j for all i,j = 1,2,3,4 and Product_{i=1..4} cos(2*Pi*b_i/n) = Product_{i=1..4} cos(2*Pi*c_i/n).at n=42A063780
- a(n) is the number of pairs of integer quadruples (b_1, b_2, b_3, b_4) and (c_1, c_2, c_3, c_4) satisfying 1 <= b_1 < b_2 < b_3 < b_4 < n, 1 <= c_1 < c_2 < c_3 < c_4 < n, b_i != c_j for all i,j = 1,2,3,4 and Product_{i=1..4} sin(2*Pi*b_i/n) = Product_{i=1..4} sin(2*Pi*c_i/n).at n=42A063781