Properties of the Number 81495

Eighty-One Thousand Four Hundred Ninety-Five

Basics

Value: 81494 → 81495 → 81496

Parity: odd

Prime: No

Previous Prime: 81463

Next Prime: 81509

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 5 × 1811

Divisors: 1, 3, 5, 9, 15, 45, 1811, 5433, 9055, 16299

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011111001010111

Octal: 237127

Duodecimal: 3B1B3

Hexadecimal: 13e57

Square: 6641435025

Square Root: 285.4732912200369

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

Start with the binary representation of the Catalan constant (A104338, A006752) = 0.91596559... = ∑_{i=1..infinity} b(i)/2ⁱ, where b(i)=1,1,1,0,1,0,1,0,0,1,1,1,1.... Then a(n-1)=∑_{i=1..k: sum_{j = 1..k} b(j)=n} b(i) * 2^i-1. In words: scan the binary digits of the number, halt at each nonzero binary digit, add a power of 2 corresponding to the place of this digit after the comma, assign current partial sum to a(n), increment n. A113860

Start with Pascal's triangle; form a rhombus by sliding down n steps from top on both sides then sliding down inwards to complete the rhombus and then deleting the inner numbers; a(n) = sum of entries on perimeter of rhombus. A81495