Properties of the Number 81005

Eighty-One Thousand Five

Basics

Value: 81004 → 81005 → 81006

Parity: odd

Prime: No

Previous Prime: 81001

Next Prime: 81013

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 5 × 17 × 953

Divisors: 1, 5, 17, 85, 953, 4765, 16201, 81005

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011110001101101

Octal: 236155

Duodecimal: 3AA65

Hexadecimal: 13c6d

Square: 6561810025

Square Root: 284.6137733842127

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

Triangle read by rows: CP(n,i) for n>=0 and 3n+1 >= i >= 0, gives the absolute value of the coefficients of the chromatic polynomial of C₃ X P_n+1 factored in the form x(x-1)ⁱ. A123531

Strong pseudoprimes to base 98. A20324

Number of nondecreasing arrangements of n+2 numbers in 0..4 with each number being the sum mod 5 of two others. A183907

Table read by antidiagonals: Place k equally spaced points on each side of a regular n-gon and join every pair of these n·k points by a chord; T(n,k) (n >= 3, k >= 0) gives the number of vertices in the resulting planar graph. A367302

a(n) = Fibonacci(4n+3) + 1, or Fibonacci(2n+1)*Lucas(2n+2). A81005