Properties of the Number 13821

Thirteen Thousand Eight Hundred Twenty-One

Basics

Value: 13820 → 13821 → 13822

Parity: odd

Prime: No

Previous Prime: 13807

Next Prime: 13829

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 17 × 271

Divisors: 1, 3, 17, 51, 271, 813, 4607, 13821

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11010111111101

Octal: 32775

Duodecimal: 7BB9

Hexadecimal: 35fd

Square: 191020041

Square Root: 117.5627492022877

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

Number of partitions p of n such that (number of numbers in p of form 3k+1) < (number of numbers in p of form 3k+2). A241737

Poincaré series for hyperbolic reflection group with Coxeter diagram o---o-(5)-o---o. A265044

Zeckendorf expansion of n: repeatedly subtract the largest Fibonacci number you can until nothing remains. Little-endian concatenation of decimals. A35515

Sum of terms in n-th row of A077316. A77318

Partial sums of A255744. A255765

Number of (w,x,y,z) with all terms in {1,...,n} and w<2x and y>3z. A212510

Smallest number that can be written in exactly n ways as a sum of distinct repdigits of its decimal digits. A131367

Solution of the complementary equation a(n) = a(n-1) + a(n-2) + n·b(n-2), where a(0) = 1, a(1) = 3, b(0) = 2, and (a(n)) and (b(n)) are increasing complementary sequences. A296286

a(n) = n*(n + 1)*(16·n - 1)/6. A304659

a(n) = 1·t(n) + 2·t(n-1) + ... + k·t(n+1-k), where k=floor((n+1)/2) and t = A000032 (Lucas numbers). A23861