20861 (number)
20,861 (twenty thousand eight hundred sixtyone) is an odd fivedigits composite number following 20860 and preceding 20862. In scientific notation, it is written as 2.0861 × 10^{4}. The sum of its digits is 17. It has a total of 2 prime factors and 4 positive divisors. There are 19,932 positive integers (up to 20861) that are relatively prime to 20861.
Basic properties
 Is Prime? No
 Number parity Odd
 Number length 5
 Sum of Digits 17
 Digital Root 8
Name
Short name  20 thousand 861 

Full name  twenty thousand eight hundred sixtyone 
Notation
Scientific notation  2.0861 × 10^{4} 

Engineering notation  20.861 × 10^{3} 
Prime Factorization of 20861
Prime Factorization 23 × 907
Composite numberω(n)  Distinct Factors  2  Total number of distinct prime factors 

Ω(n)  Total Factors  2  Total number of prime factors 
rad(n)  Radical  20861  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 20,861 is 23 × 907. Since it has a total of 2 prime factors, 20,861 is a composite number.
Divisors of 20861
4 divisors
τ(n)  Total Divisors  4  Total number of the positive divisors of n 

σ(n)  Sum of Divisors  21792  Sum of all the positive divisors of n 
s(n)  Aliquot Sum  931  Sum of the proper positive divisors of n 
A(n)  Arithmetic Mean  5448  Returns the sum of divisors (σ(n)) divided by the total number of divisors (τ(n)) 
G(n)  Geometric Mean  144.43337564427  Returns the nth root of the product of n divisors 
H(n)  Harmonic Mean  3.8291116005874  Returns the total number of divisors (τ(n)) divided by the sum of the reciprocal of each divisors 
The number 20,861 can be divided by 4 positive divisors (out of which 0 are even, and 4 are odd). The sum of these divisors (counting 20,861) is 21,792, the average is 5,448.
Other Arithmetic Functions (n = 20861)
φ(n)  Euler Totient  19932  Total number of positive integers not greater than n that are coprime to n 

λ(n)  Carmichael Lambda  9966  Smallest positive number such that a^{λ(n)} ≡ 1 (mod n) for all a coprime to n 
π(n)  Prime Pi  ≈ 2352  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 19,932 positive integers (less than 20,861) that are coprime with 20,861. And there are approximately 2,352 prime numbers less than or equal to 20,861.
Divisibility of 20861
m  2  3  4  5  6  7  8  9 

n mod m  1  2  1  1  5  1  5  8 
20,861 is not divisible by any number less than or equal to 9.
Classification of 20861
By Arithmetic functions
 Arithmetic
 Semiprime
 Deficient
Expressible via specific sums
 Polite
 Nonhypotenuse
By Powers
 Square Free
Other numbers
 LucasCarmichael
Base conversion (20861)
Base  System  Value 

2  Binary  101000101111101 
3  Ternary  1001121122 
4  Quaternary  11011331 
5  Quinary  1131421 
6  Senary  240325 
8  Octal  50575 
10  Decimal  20861 
12  Duodecimal  100a5 
16  Hexadecimal  517d 
20  Vigesimal  2c31 
36  Base36  g3h 
Basic calculations (n = 20861)
Multiplication
n×yn×2  41722 

n×3  62583 
n×4  83444 
n×5  104305 
Division
n÷yn÷2  10430.500 

n÷3  6953.666 
n÷4  5215.250 
n÷5  4172.200 
Exponentiation
n^{y}n^{2}  435181321 

n^{3}  9078317537381 
n^{4}  189382782147305041 
n^{5}  3950714218374930460301 
Nth Root
^{y}√n^{2}√n  144.43337564427 

^{3}√n  27.528235462294 
^{4}√n  12.018043752802 
^{5}√n  7.3091525236882 
20861 as geometric shapes
Circle
Radius = nDiameter  41722 

Circumference  131073.52869307 
Area  1367162441.0331 
Sphere
Radius = nVolume  38027167576522 

Surface area  5468649764.1324 
Circumference  131073.52869307 
Square
Length = nPerimeter  83444 

Area  435181321 
Diagonal  29501.909124665 
Cube
Length = nSurface area  2611087926 

Volume  9078317537381 
Space diagonal  36132.311896694 
Equilateral Triangle
Length = nPerimeter  62583 

Area  188439039.61924 
Altitude  18066.155948347 
Triangular Pyramid
Length = nSurface area  753756158.47694 

Volume  1069889982074.5 
Height  17032.935174733 
Cryptographic Hash Functions
md5  81af2033b7aa45018b5c0350490a8e8f 

sha1  9987a1e91ce1126f3d79afe1df41951acd662d17 
sha256  f598d21e478c3b72970b5cc7f1ed5953878426a167a7a79b5a1e75463754a172 
sha512  d86ceb8d2b8817fee7b3f8c96fe05f835b13cc29f67dea18f84bec98c77bbe71ed836c3942d71a879e33733cf34de8952d9a2dbb1ffeb832cacf34bc29432d6f 
ripemd160  65299a01dbc7d020a6765d8322ffa4a965301b54 