20815 (number)
20,815 (twenty thousand eight hundred fifteen) is an odd fivedigits composite number following 20814 and preceding 20816. In scientific notation, it is written as 2.0815 × 10^{4}. The sum of its digits is 16. It has a total of 3 prime factors and 8 positive divisors. There are 15,840 positive integers (up to 20815) that are relatively prime to 20815.
Basic properties
 Is Prime? No
 Number parity Odd
 Number length 5
 Sum of Digits 16
 Digital Root 7
Name
Short name  20 thousand 815 

Full name  twenty thousand eight hundred fifteen 
Notation
Scientific notation  2.0815 × 10^{4} 

Engineering notation  20.815 × 10^{3} 
Prime Factorization of 20815
Prime Factorization 5 × 23 × 181
Composite numberω(n)  Distinct Factors  3  Total number of distinct prime factors 

Ω(n)  Total Factors  3  Total number of prime factors 
rad(n)  Radical  20815  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  1  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 20,815 is 5 × 23 × 181. Since it has a total of 3 prime factors, 20,815 is a composite number.
Divisors of 20815
8 divisors
τ(n)  Total Divisors  8  Total number of the positive divisors of n 

σ(n)  Sum of Divisors  26208  Sum of all the positive divisors of n 
s(n)  Aliquot Sum  5393  Sum of the proper positive divisors of n 
A(n)  Arithmetic Mean  3276  Returns the sum of divisors (σ(n)) divided by the total number of divisors (τ(n)) 
G(n)  Geometric Mean  144.27404478977  Returns the nth root of the product of n divisors 
H(n)  Harmonic Mean  6.3537851037851  Returns the total number of divisors (τ(n)) divided by the sum of the reciprocal of each divisors 
The number 20,815 can be divided by 8 positive divisors (out of which 0 are even, and 8 are odd). The sum of these divisors (counting 20,815) is 26,208, the average is 3,276.
Other Arithmetic Functions (n = 20815)
φ(n)  Euler Totient  15840  Total number of positive integers not greater than n that are coprime to n 

λ(n)  Carmichael Lambda  1980  Smallest positive number such that a^{λ(n)} ≡ 1 (mod n) for all a coprime to n 
π(n)  Prime Pi  ≈ 2348  Total number of primes less than or equal to n 
r_{2}(n)  Sum of 2 squares  0  The number of ways n can be represented as the sum of 2 squares 
There are 15,840 positive integers (less than 20,815) that are coprime with 20,815. And there are approximately 2,348 prime numbers less than or equal to 20,815.
Divisibility of 20815
m  2  3  4  5  6  7  8  9 

n mod m  1  1  3  0  1  4  7  7 
The number 20,815 is divisible by 5.
Classification of 20815
By Arithmetic functions
 Arithmetic
 Deficient
Expressible via specific sums
 Polite
By Powers
 Square Free
Other numbers
 LucasCarmichael
 Sphenic
Base conversion (20815)
Base  System  Value 

2  Binary  101000101001111 
3  Ternary  1001112221 
4  Quaternary  11011033 
5  Quinary  1131230 
6  Senary  240211 
8  Octal  50517 
10  Decimal  20815 
12  Duodecimal  10067 
16  Hexadecimal  514f 
20  Vigesimal  2c0f 
36  Base36  g27 
Basic calculations (n = 20815)
Multiplication
n×yn×2  41630 

n×3  62445 
n×4  83260 
n×5  104075 
Division
n÷yn÷2  10407.500 

n÷3  6938.333 
n÷4  5203.750 
n÷5  4163.000 
Exponentiation
n^{y}n^{2}  433264225 

n^{3}  9018394843375 
n^{4}  187717888664850625 
n^{5}  3907347852558865759375 
Nth Root
^{y}√n^{2}√n  144.27404478977 

^{3}√n  27.507986660973 
^{4}√n  12.01141310545 
^{5}√n  7.3059262357286 
20815 as geometric shapes
Circle
Radius = nDiameter  41630 

Circumference  130784.50216894 
Area  1361139706.3233 
Sphere
Radius = nVolume  37776163982825 

Surface area  5444558825.2931 
Circumference  130784.50216894 
Square
Length = nPerimeter  83260 

Area  433264225 
Diagonal  29436.855300796 
Cube
Length = nSurface area  2599585350 

Volume  9018394843375 
Space diagonal  36052.637559546 
Equilateral Triangle
Length = nPerimeter  62445 

Area  187608912.70049 
Altitude  18026.318779773 
Triangular Pyramid
Length = nSurface area  750435650.80195 

Volume  1062828024861.4 
Height  16995.376332011 
Cryptographic Hash Functions
md5  8eee8d98fe7248f4656ae222f283cae9 

sha1  bd3cae4a466cb7293c8be495d1f1979af95a7e21 
sha256  69aea024a307f731c258a84d998a41eee49b939bd2ebcc4fb0a51024e8f78014 
sha512  daea6b2a3aa4bc80f31ba464685fe6bbb7c1ef299b3080674e3819ca9f6df1e3062a7d0001917c6b77b99bbad2cefb1fe0360a026fc100ff47a6fca7db60093f 
ripemd160  0b84253858c2161a502eea42335fec236b0d4228 