6465
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 10368
- Proper Divisor Sum (Aliquot Sum)
- 3903
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3440
- Möbius Function
- -1
- Radical
- 6465
- Omega Function (Ω)
- 3
- 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
- 23
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- For any circular arrangement of 0..n-1, let S = sum of squares of every sum of two contiguous numbers; then a(n) = # of distinct values of S.at n=33A007773
- Pair up the numbers.at n=32A030656
- a(n) = floor(n^3 / e).at n=26A032636
- Number of partitions of n such that cn(0,5) = cn(2,5) < cn(3,5) = cn(4,5) < cn(1,5).at n=60A036858
- a(n) = s(2*n) where s(0) = 0, s(1) = s(2) = 1, s(n) = abs(Sum_{k=2..n-1} (-1)^k * s(n-k) * s(k)).at n=43A072851
- Partition the concatenation 1234567... of natural numbers into successive strings which are multiples of 3 all different and > 3. (0 never taken as the most significant digit.)at n=40A077296
- Expansion of (1-x)^(-1)/(1+2*x-x^2+x^3).at n=10A077922
- a(n) = Sum_{d divides n} d*2^(n-n/d).at n=9A080267
- Row sums of triangle A175009.at n=19A175006
- Number of strictly increasing arrangements of 4 numbers in -(n+2)..(n+2) with sum zero.at n=28A188182
- Odd numbers producing 5 odd numbers in the Collatz iteration.at n=36A198588
- Number of -n..n arrays x(0..5) of 6 elements with zero sum and no element more than one greater than the previous.at n=7A199850
- Number of 2 X 2 matrices with all terms in {0,1,...,n} and (sum of terms) = n + 4.at n=28A210376
- Partial sums of A072272.at n=48A253908
- Number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 211", based on the 5-celled von Neumann neighborhood.at n=41A270897
- In the binary race of Pi, where the race leader changes.at n=11A278920
- Numbers k with exactly three distinct prime factors and such that cototient(k) is a square.at n=21A306670
- Numbers k such that floor(prime(k)/k) < floor(prime(k+1)/(k+1)).at n=13A308082
- a(n) = (4*n^3 + 12*n^2 - 4*n + 3)/3.at n=16A322594
- (A331763(n) - A331755(n+1))/2.at n=20A335687