Properties of the Number 12821

Twelve Thousand Eight Hundred Twenty-One

Basics

Value: 12820 → 12821 → 12822

Parity: odd

Prime: Yes

Previous Prime: 12809

Next Prime: 12823

Digit Sum: 14

Digital Root: 5

Palindrome: Yes

Factorization: 12821

Divisors: 1, 12821

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11001000010101

Octal: 31025

Duodecimal: 7505

Hexadecimal: 3215

Square: 164378041

Square Root: 113.22985472038724

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

Palindromic primes: prime numbers whose decimal expansion is a palindrome. A2385

Initial primes of Cunningham chains of first type with length exactly 3. Primes in A059453 that survive as primes just two "2p+1 iterations", forming chains of exactly 3 terms. A59762

Mountain primes. A134951

Lesser of twin primes whose average is 6 times a prime. A60213

Prime power decimal palindromes. A84092

Number of equivalence classes of compositions of n where two compositions a,b are considered equivalent if the summands of a can be permuted into the summands of b with an even number of transpositions. A218004

T(n,k)=Number of nXk 0..2 arrays with every repeated value in every row greater than or equal to, and in every column greater than, the previous repeated value. A268026

T(n,k)=Number of length-n 0..k arrays with no repeated value greater than the previous repeated value. A269435

Numbers n such that φ(n) + σ(n) = n + reversal(n). A69217

Strobogrammatic primes: the same upside down (calculator-style numerals). A18847