806
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 1344
- Proper Divisor Sum (Aliquot Sum)
- 538
- 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
- 360
- Möbius Function
- -1
- Radical
- 806
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 20
- Smith 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
- yes
- Odd
- no
Names
- German
- achthundertsechs· ordinal: achthundertsechsste
- English
- eight hundred six· ordinal: eight hundred sixth
- Spanish
- ochocientos seis· ordinal: 806º
- French
- huit cent six· ordinal: huit cent sixième
- Italian
- ottocentosei· ordinal: 806º
- Latin
- octingenti sex· ordinal: 806.
- Portuguese
- oitocentos e seis· ordinal: 806º
Appears in sequences
- Related to population of numbers of form x^2 + y^2.at n=11A000709
- Numbers beginning with letter 'e' in English.at n=19A000873
- Number of sublattices of index n in generic 3-dimensional lattice.at n=24A001001
- Expansion of 1/((1-x)^2*(1-x^2)*(1-x^5)).at n=32A001304
- Numbers in which every digit contains at least one loop (version 1).at n=33A001743
- Genus of modular group Gamma(n) = genus of modular curve Chi(n).at n=27A001767
- Sum of totient function: a(n) = Sum_{k=1..n} phi(k), cf. A000010.at n=51A002088
- Numbers of the form (p^2 - 1)/120 where p is 1 or prime.at n=29A002381
- a(n) = 2*a(n-1) + 9*a(n-2), with a(0) = 0, a(1) = 1.at n=6A002534
- Numbers that are the sum of 12 positive 5th powers.at n=38A003357
- Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals up to rotation and reflection.at n=23A003453
- Gaussian binomial coefficient [ n,2 ] for q=5.at n=2A006111
- Gaussian binomial coefficient [ 2n,n ] for q=5.at n=2A006114
- Gaussian binomial coefficient [ n,n/2 ] for q=5.at n=4A006115
- a(n) = Sum_{k=1..n-1} k XOR n-k.at n=33A006582
- A grasshopper sequence: closed under n -> 2n+2 and 6n+6.at n=48A007319
- Add 7, then reverse digits.at n=29A007398
- Shifts left when inverse Moebius transform applied twice.at n=23A007557
- Number of edge-labeled series-reduced trees with n nodes.at n=6A007831
- Coordination sequence T3 for Zeolite Code MFI.at n=18A008166