Properties of the Number 81018

Eighty-One Thousand Eighteen

Basics

Value: 81017 → 81018 → 81019

Parity: even

Prime: No

Previous Prime: 81017

Next Prime: 81019

Digit Sum: 18

Digital Root: 9

Palindrome: Yes

Factorization: 2 × 3 ² × 7 × 643

Divisors: 1, 2, 3, 6, 7, 9, 14, 18, 21, 42

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011110001111010

Octal: 236172

Duodecimal: 3AA76

Hexadecimal: 13c7a

Square: 6563916324

Square Root: 284.6366104351301

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

Numbers with mirror symmetry about middle. A6072

Strobogrammatic cyclops numbers. A153806

G.f. A(x) satisfies: A(x) = Series_Reversion( x - 2·x*A(x) - Integral 2·A(x) dx ). A259610

Records in A073053 starting from a(1). A305395

Base 10 palindromes that start with 8. A43043

Beginning with 1, palindromes such that successive differences are distinct primes. A88052

Palindromes sandwiched between twin primes. A113838

a(n) = (Lucas(4n+1)-1)/5, or Fibonacci(2n)*Fibonacci(2n+1), or A081017(n)/5. A81018

G.f. A(x) satisfies: A(x)*A'(x) = Series_Reversion( x - 2·x*A(x)*A'(x) - A(x)² ). A259612

The simple continued fraction expansion of F(x) := ∏_{n >= 0} (1 - x^4·n+3)/(1 - x^4·n+1) when x = (1/2)*(9 - sqrt(77)). A221367