Properties of the Number 81003

Eighty-One Thousand Three

Basics

Value: 81002 → 81003 → 81004

Parity: odd

Prime: No

Previous Prime: 81001

Next Prime: 81013

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 3 × 13 × 31 × 67

Divisors: 1, 3, 13, 31, 39, 67, 93, 201, 403, 871

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011110001101011

Octal: 236153

Duodecimal: 3AA63

Hexadecimal: 13c6b

Square: 6561486009

Square Root: 284.6102598291214

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) = sqrt(σ(2·m²)), where m = A097023(n), i.e., σ(2·m²) is a square. A163764

Triangular numbers whose sum of aliquot divisors is a prime number. A83676

Numbers that cannot be expressed as a sum of 2 triangular numbers and a power of 2. A112665

Expansion of 2/((2+x)*sqrt(1-4·x)-x). A116396

Integers m such that A342805(m) = m+3. A342806

Numbers that start a run of four consecutive triangular numbers with four distinct prime factors. A349773

Triangular numbers for which the sum of the digits is a pentagonal number. A117305

Triangular numbers T such that T+10 is the next prime after T. A129540

a(n) = Fibonacci(4n+1) + 1, or Fibonacci(2n+1)*Lucas(2n). A81003

Number of nX3 0..1 arrays with no element equal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. A279489