Properties of the Number 20081

Twenty Thousand Eighty-One

Basics

Value: 20080 → 20081 → 20082

Parity: odd

Prime: No

Previous Prime: 20071

Next Prime: 20089

Digit Sum: 11

Digital Root: 2

Palindrome: No

Factorization: 43 × 467

Divisors: 1, 43, 467, 20081

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 100111001110001

Octal: 47161

Duodecimal: B755

Hexadecimal: 4e71

Square: 403246561

Square Root: 141.70744511139844

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

Number of distinct row/column permutations of plane partitions of n. A321645

Sum of next n composite numbers. A72475

Irregular triangle read by rows: the right-hand side of the triangle in A349815. A349816

Number of n X 3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 8 king-move adjacent elements, with upper left element zero. A305247

a(n) = 2^{2·n - HammingWeight(n}) * [xⁿ] ((1 - x)^-5/2 - (x - 1)^-2). A380951

Composite numbers not divisible by 7 which in base 7 contain their largest proper factor as a substring. A63877

Number of ways to build a contiguous building with n LEGO blocks of size 1 X 5 on top of a fixed block of the same size so that the building is flat, i.e., with all blocks in parallel position and symmetric after a rotation by 180 degrees. A123793

Decimal expansion of Shapiro's cyclic sum constant μ. A86278

a(n) = floor( γ(n + 1/6)/γ(1/6) ). A20081

Integers n such that 2·10ⁿ + 81 is a prime number. A110920