Properties of the Number 81915

Eighty-One Thousand Nine Hundred Fifteen

Basics

Value: 81914 → 81915 → 81916

Parity: odd

Prime: No

Previous Prime: 81901

Next Prime: 81919

Digit Sum: 24

Digital Root: 6

Palindrome: No

Factorization: 3 × 5 × 43 × 127

Divisors: 1, 3, 5, 15, 43, 127, 129, 215, 381, 635

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011111111111011

Octal: 237773

Duodecimal: 3B4A3

Hexadecimal: 13ffb

Square: 6710067225

Square Root: 286.20796634615186

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=0..n (k+1) * A026637(n,k). A26970

Sequence of sums of alternating increasing powers of 2. A79360

A Jacobsthal-Lucas convolution. A99429

Partial sums of A162255. A164053

Positive integers with the property that if the base-4 representation is reversed the result is three times the original number. A223078

Number of magic labelings with magic sum n of 3rd graph shown in link. A244871

Trajectory of 3 under map n->17n+1 if n odd, n->n/2 if n even. A37106

a(n) = 4ⁿ*(n³ - 3·n² + 2·n + 384)/384. A81915

a(n) is the number of edges of a regular polygon P with the property that packing n nonoverlapping equal circles inside P, arranged in a configuration with dihedral symmetry D_2m with m >= 3, maximizes the packing density. A343262