Properties of the Number 18891

Eighteen Thousand Eight Hundred Ninety-One

Basics

Value: 18890 → 18891 → 18892

Parity: odd

Prime: No

Previous Prime: 18869

Next Prime: 18899

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 2099

Divisors: 1, 3, 9, 2099, 6297, 18891

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100100111001011

Octal: 44713

Duodecimal: AB23

Hexadecimal: 49cb

Square: 356869881

Square Root: 137.4445342674637

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) = 81·n² - 118·n + 43. A156677

a(n) = ∑_{k=0..floor(2·n/5)} (k+1) * binomial(k,2·n-5·k). A392268

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 89", based on the 5-celled von Neumann neighborhood. A270131

a(n) = ∑_{k=0..floor(n/2)} A027144(n-k, k). A27154

Partial sums of A057429. A172512

a(1)=1; for n>1, a(n) = a(n-1) + lcm(a(n-1),n). A135504

Number of (2+1) X (n+1) 0..2 arrays with every element both >= and <= some horizontal or antidiagonal neighbor. A232259

Number of positive knots with n crossings. A18891

Number of (n+2) X (1+2) 0..3 arrays with every consecutive three elements in every row and diagonal having one or two distinct values, and in every column and antidiagonal having two or three distinct values, and new values 0 upwards introduced in row major order. A252841