Properties of the Number 21859

Twenty-One Thousand Eight Hundred Fifty-Nine

Basics

Value: 21858 → 21859 → 21860

Parity: odd

Prime: Yes

Previous Prime: 21851

Next Prime: 21863

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 21859

Divisors: 1, 21859

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010101100011

Octal: 52543

Duodecimal: 10797

Hexadecimal: 5563

Square: 477815881

Square Root: 147.84789481084943

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

a(n) = ∑_i=0..n ∑_j=0..n T(i,j), T given by A026747. A26756

Sum of primes p with n² < p < (n+1)². A108314

Number of partitions of n such that the number of even parts is a part and the number of odd parts is a part. A240575

T(n,k)=Number of nXk 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4. A240760

a(1) = 2. Let k >= 1 be the minimal integer such that 2·k*a(n-1) + 1 has at least one prime divisor which is not already in the sequence. Then a(n) is the smallest such divisor. A174162

Sum of tail length of S over all 2ⁿ strings S consisting of n 2's and 3's. A216813

A set of nine consecutive primes forming a 3 X 3 semimagic square with the smallest magic constant (65573). A265614

Let F(g,p) be the frequency of g up to prime nextprime(p+1). Primes p such that F(2,p) = F(4,p) and g = 2 or 4. A274122

First term of weak prime sextet: p(m+1)-p(m) < p(m+2)-p(m+1) < p(m+3)-p(m+2) < p(m+4)-p(m+3) < p(m+5)-p(m+4). A54828

Primes that do not divide any term of the Lucas 4-step sequence A073817. A106300