666 (number)
666 (six hundred sixtysix) is an even threedigits composite number following 665 and preceding 667. In scientific notation, it is written as 6.66 × 10^{2}. The sum of its digits is 18. It has a total of 4 prime factors and 12 positive divisors. There are 216 positive integers (up to 666) that are relatively prime to 666.
Basic properties
 Is Prime? No
 Number parity Even
 Number length 3
 Sum of Digits 18
 Digital Root 9
Name
Short name  666 

Full name  six hundred sixtysix 
Notation
Scientific notation  6.66 × 10^{2} 

Engineering notation  666 × 10^{0} 
Prime Factorization of 666
Prime Factorization 2 × 3^{2} × 37
Composite numberω(n)  Distinct Factors  3  Total number of distinct prime factors 

Ω(n)  Total Factors  4  Total number of prime factors 
rad(n)  Radical  222  Product of the distinct prime numbers 
λ(n)  Liouville Lambda  1  Returns the parity of Ω(n), such that λ(n) = (1)^{Ω(n)} 
μ(n)  Mobius Mu  0  Returns:

Λ(n)  Mangoldt function  0  Returns log(p) if n is a power p^{k} of any prime p (for any k >= 1), else returns 0 
The prime factorization of 666 is 2 × 3^{2} × 37. Since it has a total of 4 prime factors, 666 is a composite number.
Divisors of 666
12 divisors
τ(n)  Total Divisors  12  Total number of the positive divisors of n 

σ(n)  Sum of Divisors  1482  Sum of all the positive divisors of n 
s(n)  Aliquot Sum  816  Sum of the proper positive divisors of n 
A(n)  Arithmetic Mean  123.5  Returns the sum of divisors (σ(n)) divided by the total number of divisors (τ(n)) 
G(n)  Geometric Mean  25.806975801128  Returns the nth root of the product of n divisors 
H(n)  Harmonic Mean  5.3927125506073  Returns the total number of divisors (τ(n)) divided by the sum of the reciprocal of each divisors 
The number 666 can be divided by 12 positive divisors (out of which 6 are even, and 6 are odd). The sum of these divisors (counting 666) is 1,482, the average is 12,3.5.
Other Arithmetic Functions (n = 666)
φ(n)  Euler Totient  216  Total number of positive integers not greater than n that are coprime to n 

λ(n)  Carmichael Lambda  36  Smallest positive number such that a^{λ(n)} ≡ 1 (mod n) for all a coprime to n 
π(n)  Prime Pi  ≈ 122  Total number of primes less than or equal to n 
r_{2}(n)  Sum of 2 squares  8  The number of ways n can be represented as the sum of 2 squares 
There are 216 positive integers (less than 666) that are coprime with 666. And there are approximately 122 prime numbers less than or equal to 666.
Divisibility of 666
m  2  3  4  5  6  7  8  9 

n mod m  0  0  2  1  0  1  2  0 
The number 666 is divisible by 2, 3, 6 and 9.
Classification of 666
By Arithmetic functions
 Abundant
Expressible via specific sums
 Polite
 Practical
By Shape (2D, noncentered)
 Triangle
Base conversion (666)
Base  System  Value 

2  Binary  1010011010 
3  Ternary  220200 
4  Quaternary  22122 
5  Quinary  10131 
6  Senary  3030 
8  Octal  1232 
10  Decimal  666 
12  Duodecimal  476 
16  Hexadecimal  29a 
20  Vigesimal  1d6 
36  Base36  ii 
Basic calculations (n = 666)
Multiplication
n×yn×2  1332 

n×3  1998 
n×4  2664 
n×5  3330 
Division
n÷yn÷2  333.000 

n÷3  222.000 
n÷4  166.500 
n÷5  133.200 
Exponentiation
n^{y}n^{2}  443556 

n^{3}  295408296 
n^{4}  196741925136 
n^{5}  131030122140576 
Nth Root
^{y}√n^{2}√n  25.806975801128 

^{3}√n  8.732891741296 
^{4}√n  5.0800566730232 
^{5}√n  3.6702432264521 
666 as geometric shapes
Circle
Radius = nDiameter  1332 

Circumference  4184.6014145816 
Area  1393472.2710557 
Sphere
Radius = nVolume  1237403376.6974 

Surface area  5573889.0842227 
Circumference  4184.6014145816 
Square
Length = nPerimeter  2664 

Area  443556 
Diagonal  941.86623254048 
Cube
Length = nSurface area  2661336 

Volume  295408296 
Space diagonal  1153.5458378409 
Equilateral Triangle
Length = nPerimeter  1998 

Area  192065.38200051 
Altitude  576.77291892044 
Triangular Pyramid
Length = nSurface area  768261.52800202 

Volume  34814201.553394 
Height  543.78672289787 
Cryptographic Hash Functions
md5  fae0b27c451c728867a567e8c1bb4e53 

sha1  cd3f0c85b158c08a2b113464991810cf2cdfc387 
sha256  c7e616822f366fb1b5e0756af498cc11d2c0862edcb32ca65882f622ff39de1b 
sha512  2acdcd7a6497cc2702c9f3cf87d4ac93562676841bc518ccd7f0a0061b4a58c4928b9115e2fdc32dfe3e3bdf80a2119a6d39c3125b16e0e7085a65c3777585bc 
ripemd160  58751ef16a600a191dcf7aa1d4326d55193c5f08 