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Properties of the Number 21339

Twenty-One Thousand Three Hundred Thirty-Nine

Basics

Value: 21338 → 21339 → 21340

Parity: odd

Prime: No

Previous Prime: 21323

Next Prime: 21341

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 2 × 2371

Divisors: 1, 3, 9, 2371, 7113, 21339

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001101011011

Octal: 51533

Duodecimal: 10423

Hexadecimal: 535b

Square: 455352921

Square Root: 146.07874588727822

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) = ∑k<=n A000203(k)*(n-k+1), where A000203(m) is the sum of divisors of m. A175254
Trajectory of 18 under iteration of the map k -> A087712(k). A77960
Number of partitions p of n such that the number of parts is not a part and max(p) - min(p) is not a part. A241385
a(n) = 729·n - 531. A156771
Bitwise encoding of the state of a 1D cellular automaton after n steps from ...111000... where adjacent cells swap 01 <-> 10 when within triples 110 or 011. A359303
Number of 4-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero with no three beads in a row equal. A209345
Partial sums of A256970. A256971
Isomers of polyenes attached to benzene (see Cyvin et al. for precise definition). A121097
a(n) = f(n,n) where f(0,n) = f(n,0) = n! and f(m,n) = f(m-1,n) + f(m,n-1) + f(m-1,n-1). A346374
a(n) is the number of coverings of 1..n by cyclic words of length n, such that each value from 1 to n appears precisely 3 times. That is, the union of all the letters in all of the words of a given covering is the multiset {1,1,1,2,2,2,...,n,n,n}. Repeats of words are not allowed in a given covering. A110105