216991 (number)
216,991 (two hundred sixteen thousand nine hundred ninetyone) is an odd sixdigits prime number following 216990 and preceding 216992. In scientific notation, it is written as 2.16991 × 10^{5}. The sum of its digits is 28. It has a total of 1 prime factor and 2 positive divisors. There are 216,990 positive integers (up to 216991) that are relatively prime to 216991.
Basic properties
 Is Prime? Yes
 Number parity Odd
 Number length 6
 Sum of Digits 28
 Digital Root 1
Name
Short name  216 thousand 991 

Full name  two hundred sixteen thousand nine hundred ninetyone 
Notation
Scientific notation  2.16991 × 10^{5} 

Engineering notation  216.991 × 10^{3} 
Prime Factorization of 216991
Prime Factorization 216991
Prime numberω(n)  Distinct Factors  1  Total number of distinct prime factors 

Ω(n)  Total Factors  1  Total number of prime factors 
rad(n)  Radical  216991  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  12.287611157008  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 216,991 is 216991. Since it has a total of 1 prime factor, 216,991 is a prime number.
Divisors of 216991
2 divisors
τ(n)  Total Divisors  2  Total number of the positive divisors of n 

σ(n)  Sum of Divisors  216992  Sum of all the positive divisors of n 
s(n)  Aliquot Sum  1  Sum of the proper positive divisors of n 
A(n)  Arithmetic Mean  108496  Returns the sum of divisors (σ(n)) divided by the total number of divisors (τ(n)) 
G(n)  Geometric Mean  465.82292773113  Returns the nth root of the product of n divisors 
H(n)  Harmonic Mean  1.9999907830703  Returns the total number of divisors (τ(n)) divided by the sum of the reciprocal of each divisors 
The number 216,991 can be divided by 2 positive divisors (out of which 0 are even, and 2 are odd). The sum of these divisors (counting 216,991) is 216,992, the average is 108,496.
Other Arithmetic Functions (n = 216991)
φ(n)  Euler Totient  216990  Total number of positive integers not greater than n that are coprime to n 

λ(n)  Carmichael Lambda  216990  Smallest positive number such that a^{λ(n)} ≡ 1 (mod n) for all a coprime to n 
π(n)  Prime Pi  ≈ 19318  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 216,990 positive integers (less than 216,991) that are coprime with 216,991. And there are approximately 19,318 prime numbers less than or equal to 216,991.
Divisibility of 216991
m  2  3  4  5  6  7  8  9 

n mod m  1  1  3  1  1  5  7  1 
216,991 is not divisible by any number less than or equal to 9.
Classification of 216991
By Arithmetic functions
 Arithmetic
 Prime
 Deficient
Expressible via specific sums
 Polite
 Nonhypotenuse
By Powers
 Prime Power
 Square Free
Base conversion (216991)
Base  System  Value 

2  Binary  110100111110011111 
3  Ternary  102000122201 
4  Quaternary  310332133 
5  Quinary  23420431 
6  Senary  4352331 
8  Octal  647637 
10  Decimal  216991 
12  Duodecimal  a56a7 
16  Hexadecimal  34f9f 
20  Vigesimal  1729b 
36  Base36  4nfj 
Basic calculations (n = 216991)
Multiplication
n×yn×2  433982 

n×3  650973 
n×4  867964 
n×5  1084955 
Division
n÷yn÷2  108495.500 

n÷3  72330.333 
n÷4  54247.750 
n÷5  43398.200 
Exponentiation
n^{y}n^{2}  47085094081 

n^{3}  10217041649730271 
n^{4}  2217006084616621234561 
n^{5}  481070367307045258308625951 
Nth Root
^{y}√n^{2}√n  465.82292773113 

^{3}√n  60.091619286489 
^{4}√n  21.582931398008 
^{5}√n  11.675845625733 
216991 as geometric shapes
Circle
Radius = nDiameter  433982 

Circumference  1363394.6629902 
Area  147922185658.45 
Sphere
Radius = nVolume  4.2797043984285E+16 

Surface area  591688742633.82 
Circumference  1363394.6629902 
Square
Length = nPerimeter  867964 

Area  47085094081 
Diagonal  306871.6151129 
Cube
Length = nSurface area  282510564486 

Volume  10217041649730271 
Space diagonal  375839.43678518 
Equilateral Triangle
Length = nPerimeter  650973 

Area  20388443806.863 
Altitude  187919.71839259 
Triangular Pyramid
Length = nSurface area  81553775227.453 

Volume  1.2040899056983E+15 
Height  177172.40959209 
Cryptographic Hash Functions
md5  8ba9e61652da12f19fee8e8be73ca53a 

sha1  51e48ae2bcb0741d7886f4bf0d617df0632cc8a7 
sha256  c9d706cd05bf5b7cce48cf92e48fe97788dd58a5fc4ca23b28bdff7d9d35345b 
sha512  8fb3d4aed39727aee4ab8c7e07fcf5bb0cf6958c78249b910ea5fadeb9937ff82478692028dfffe747000551b087fc7eacbf4c672270dcbfc81f3061bb88e5d0 
ripemd160  42b7a7161cb5cb0289d16efaa88c2114bc5b5aca 