Properties of the Number 18281

Eighteen Thousand Two Hundred Eighty-One

Basics

Value: 18280 → 18281 → 18282

Parity: odd

Prime: No

Previous Prime: 18269

Next Prime: 18287

Digit Sum: 20

Digital Root: 2

Palindrome: Yes

Factorization: 101 × 181

Divisors: 1, 101, 181, 18281

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 100011101101001

Octal: 43551

Duodecimal: A6B5

Hexadecimal: 4769

Square: 334194961

Square Root: 135.20724832641184

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

Numbers k such that k concatenated with k+5 gives the product of two numbers which differ by 5. A116193

Expansion of x/((1-x-x³)*(1-x)³). A226405

Palindromes with exactly 2 palindromic prime factors (counted with multiplicity), and no other prime factors. A46376

Numbers k such that k concatenated with k-1 gives the product of two numbers which differ by 7. A116152

Palindromes with exactly 2 distinct palindromic prime factors. A46408

Least k such that gcd(prime(k+1)-1, prime(k)-1) = 2n. A67605

Nonprime numbers with all divisors starting and ending with digit 1. A208261

Irregular triangle read by rows: row n consists of the coefficients in the expansion of the polynomial x*(x² - 2) + x*(((v - w)/2)ⁿ + ((v + w)/2)ⁿ), where v = 3 + 2·x and w = sqrt(5 + 4·x). A316659

a(n) = 4^2·n² * ∏_1<=j,k<=n (1 - sin(j*π/(2·n+1))² * cos(k*π/(2·n+1))²). A340295

Composite palindromes whose sum of prime factors is palindromic (counted with multiplicity). A46354