Properties of the Number 18081

Eighteen Thousand Eighty-One

Basics

Value: 18080 → 18081 → 18082

Parity: odd

Prime: No

Previous Prime: 18077

Next Prime: 18089

Digit Sum: 18

Digital Root: 9

Palindrome: Yes

Factorization: 3 ² × 7 ² × 41

Divisors: 1, 3, 7, 9, 21, 41, 49, 63, 123, 147

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 100011010100001

Octal: 43241

Duodecimal: A569

Hexadecimal: 46a1

Square: 326922561

Square Root: 134.46560898608982

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) = (2·n - 1)*n². A15237

Numbers with mirror symmetry about middle. A6072

Palindromic cyclops numbers. A138131

Palindromic and divisible by 9. A45644

Strobogrammatic cyclops numbers. A153806

Row sums of the triangle in A199332. A199771

Odd composite integers m such that A000032(m-J(m,5)) == 2·J(m,5) (mod m), where J(m,5) is the Jacobi symbol. A339125

Row sums of A128623. A128624

Palindromes with exactly 5 prime factors (counted with multiplicity). A46331

Number of 0..n arrays x(0..2) of 3 elements with each no smaller than the sum of its previous elements modulo (n+1). A200252