Properties of the Number 20281

Twenty Thousand Two Hundred Eighty-One

Basics

Value: 20280 → 20281 → 20282

Parity: odd

Prime: No

Previous Prime: 20269

Next Prime: 20287

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 17 × 1193

Divisors: 1, 17, 1193, 20281

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100111100111001

Octal: 47471

Duodecimal: B8A1

Hexadecimal: 4f39

Square: 411318961

Square Root: 142.41137595009747

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) = 30·n² + 1. A158558

Numbers n such that n and prime(n) end with the same three digits. A67841

a(1)=1. a(n) = a(n-1) + sum of the triangular numbers which are among the first (n-1) terms of the sequence. A100963

a(n) = 676·n + 1. A158386

Numbers k such that the continued fraction for sqrt(k) has period 35. A20374

Number of (n+1) X 9 binary arrays with every 2 X 2 subblock commuting with each of its horizontal and vertical 2 X 2 subblock neighbors. A186461

Sequence defined by the recurrence formula a(n+1)=sum(a(p)*a(n-p)+k,p=0..n)+l for n>=1, with here a(0)=1, a(1)=9, k=0 and l=-1. A177166

G.f. A(x) satisfies: (1 - x) = A(x)*A(x²)²*A(x³)³*A(x⁴)⁴* ... *A(x^k)^k* ... A307656

T(n,k)=Number of (n+1)X(k+1) binary arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors. A186462

Values k for primitive solutions to k⁵ + a⁵ + b⁵ = c⁵ + d⁵ + e⁵ with k >= a >= b >= 0 and k > c >= d >= e >= 0, repetitions allowed. A376289