Properties of the Number 21839

Twenty-One Thousand Eight Hundred Thirty-Nine

Basics

Value: 21838 → 21839 → 21840

Parity: odd

Prime: Yes

Previous Prime: 21821

Next Prime: 21841

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 21839

Divisors: 1, 21839

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010101001111

Octal: 52517

Duodecimal: 1077B

Hexadecimal: 554f

Square: 476941921

Square Root: 147.78024225179766

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

Primes p such that the number of distinct prime divisors of all composite numbers between p and the next prime is 5. A75585

List of primes p1 such that (p1,p2) are twin primes where both 2·p1+p2 and p1+2·p2 are primes. A174920

a(n) is the smallest·such that the quotient d(x+1)/d(x) equals n, where d = A000005. A80371

Primes of the form 2·n² + 2·n - 1. A98828

Consider the array T(n, m) = m-th prime of the form n·i(i+1)/2 +/- 1. This sequence is the main diagonal. A125765

Smaller of twin primes whose middle term is a multiple of A002110(4)=210. A60230

Lesser of twin primes p1 such that p1+(p2²-p1²) and p2+(p2²-p1²) are prime numbers. A174922

Primes p dividing every A167859(m) from m=(p-1)/2 to m=(p-1). A167860

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

Numbers k where records occur for d(k+1)/d(k), where d(k) is A000005(k). A282531