21865 (number)
21,865 (twentyone thousand eight hundred sixtyfive) is an odd fivedigits composite number following 21864 and preceding 21866. In scientific notation, it is written as 2.1865 × 10^{4}. The sum of its digits is 22. It has a total of 2 prime factors and 4 positive divisors. There are 17,488 positive integers (up to 21865) that are relatively prime to 21865.
Basic properties
 Is Prime? No
 Number parity Odd
 Number length 5
 Sum of Digits 22
 Digital Root 4
Name
Short name  21 thousand 865 

Full name  twentyone thousand eight hundred sixtyfive 
Notation
Scientific notation  2.1865 × 10^{4} 

Engineering notation  21.865 × 10^{3} 
Prime Factorization of 21865
Prime Factorization 5 × 4373
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  21865  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 21,865 is 5 × 4373. Since it has a total of 2 prime factors, 21,865 is a composite number.
Divisors of 21865
4 divisors
τ(n)  Total Divisors  4  Total number of the positive divisors of n 

σ(n)  Sum of Divisors  26244  Sum of all the positive divisors of n 
s(n)  Aliquot Sum  4379  Sum of the proper positive divisors of n 
A(n)  Arithmetic Mean  6561  Returns the sum of divisors (σ(n)) divided by the total number of divisors (τ(n)) 
G(n)  Geometric Mean  147.86818454286  Returns the nth root of the product of n divisors 
H(n)  Harmonic Mean  3.332571254382  Returns the total number of divisors (τ(n)) divided by the sum of the reciprocal of each divisors 
The number 21,865 can be divided by 4 positive divisors (out of which 0 are even, and 4 are odd). The sum of these divisors (counting 21,865) is 26,244, the average is 6,561.
Other Arithmetic Functions (n = 21865)
φ(n)  Euler Totient  17488  Total number of positive integers not greater than n that are coprime to n 

λ(n)  Carmichael Lambda  4372  Smallest positive number such that a^{λ(n)} ≡ 1 (mod n) for all a coprime to n 
π(n)  Prime Pi  ≈ 2452  Total number of primes less than or equal to n 
r_{2}(n)  Sum of 2 squares  16  The number of ways n can be represented as the sum of 2 squares 
There are 17,488 positive integers (less than 21,865) that are coprime with 21,865. And there are approximately 2,452 prime numbers less than or equal to 21,865.
Divisibility of 21865
m  2  3  4  5  6  7  8  9 

n mod m  1  1  1  0  1  4  1  4 
The number 21,865 is divisible by 5.
Classification of 21865
By Arithmetic functions
 Arithmetic
 Semiprime
 Deficient
Expressible via specific sums
 Polite
By Powers
 Square Free
Other numbers
 LucasCarmichael
Base conversion (21865)
Base  System  Value 

2  Binary  101010101101001 
3  Ternary  1002222211 
4  Quaternary  11111221 
5  Quinary  1144430 
6  Senary  245121 
8  Octal  52551 
10  Decimal  21865 
12  Duodecimal  107a1 
16  Hexadecimal  5569 
20  Vigesimal  2ed5 
36  Base36  gvd 
Basic calculations (n = 21865)
Multiplication
n×yn×2  43730 

n×3  65595 
n×4  87460 
n×5  109325 
Division
n÷yn÷2  10932.500 

n÷3  7288.333 
n÷4  5466.250 
n÷5  4373.000 
Exponentiation
n^{y}n^{2}  478078225 

n^{3}  10453180389625 
n^{4}  228558789219150625 
n^{5}  4997437926276728415625 
Nth Root
^{y}√n^{2}√n  147.86818454286 

^{3}√n  27.962961230312 
^{4}√n  12.160106271857 
^{5}√n  7.3781910454167 
21865 as geometric shapes
Circle
Radius = nDiameter  43730 

Circumference  137381.84674148 
Area  1501927039.5012 
Sphere
Radius = nVolume  43786179624926 

Surface area  6007708158.005 
Circumference  137381.84674148 
Square
Length = nPerimeter  87460 

Area  478078225 
Diagonal  30921.779541288 
Cube
Length = nSurface area  2868469350 

Volume  10453180389625 
Space diagonal  37871.290907494 
Equilateral Triangle
Length = nPerimeter  65595 

Area  207013943.92309 
Altitude  18935.645453747 
Triangular Pyramid
Length = nSurface area  828055775.69235 

Volume  1231919123078.3 
Height  17852.697741985 
Cryptographic Hash Functions
md5  1d715bae5c24c728757dc4de28ae388f 

sha1  33b9f7804743a58b9d30e2c506a170ec17552480 
sha256  4aba420d3376bb96ad97c6bd81b517d6f6d3b26509f7df5fd7145eb67f1dbaf3 
sha512  c54004f806f165dc5ba5fcc0a7aa12acd42e064b07c829627fd8467f7dce5935e400ea9a7d82306a6814f391308bcce51d0a9b1525e0b195fda11c3e873dfa08 
ripemd160  d71acf3c6c51ae5165af5df407e98090aa4ca085 