Properties of the Number 81819

Eighty-One Thousand Eight Hundred Nineteen

Basics

Value: 81818 → 81819 → 81820

Parity: odd

Prime: No

Previous Prime: 81817

Next Prime: 81839

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 9091

Divisors: 1, 3, 9, 9091, 27273, 81819

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011111110011011

Octal: 237633

Duodecimal: 3B423

Hexadecimal: 13f9b

Square: 6694348761

Square Root: 286.0402069639861

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

Divisors of 9999999999. A27895

Another 3-way generalization of series-parallel networks with n labeled edges. A58562

Numbers m such that the largest digit in the decimal expansion of 1/m is 2. A341383

Numbers k of the form a - b + c, such that k³ equals the decimal concatenation a//b//c and numbers k, b, and c have the same number of digits. A259379

Numbers n dividing every cyclic permutation of n². A178028

Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 846", based on the 5-celled von Neumann neighborhood. A284298

Numbers k that are divisors of the number formed by concatenating (k-1), k and (k+1), in that order. A88877

Let n be the number whose square n² has the decimal expansion { d(1) d(2) ... d(D) }, and let q be the corresponding number whose decimal expansion is { d(2) d(3) ... d(D) d(1)}. Sequence lists numbers n dividing q. A177928

a(n) = n² concatenated with reverse(n²) divided by 11. A84009

Numbers n dividing every cyclic permutation of n⁴. A242740