Properties of the Number 3781

Three Thousand Seven Hundred Eighty-One

Basics

Value: 3780 → 3781 → 3782

Parity: odd

Prime: No

Previous Prime: 3779

Next Prime: 3793

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 19 × 199

Divisors: 1, 19, 199, 3781

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111011000101

Octal: 7305

Duodecimal: 2231

Hexadecimal: ec5

Square: 14295961

Square Root: 61.48983655857283

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

Hex (or centered hexagonal) numbers: 3·n*(n+1)+1 (crystal ball sequence for hexagonal lattice). A3215

Centered 10-gonal numbers. A62786

Preperiod (or threshold) of orbit of Post's {00, 1101} tag system applied to the word (100)ⁿ, or -1 if this word has an unbounded trajectory. A284119

Generalized 22-gonal (or icosidigonal) numbers: m*(10·m - 9) with m = 0, +1, -1, +2, -2, +3, -3, ... A303299

Generalized 24-gonal (or icositetragonal) numbers: m*(11·m - 10) with m = 0, +1, -1, +2, -2, +3, -3, ... A303814

Generalized Fibonacci numbers: a(n) = a(n-1) + 9·a(n-2). A15445

Pinwheel numbers: a(n) = 2·n² + 6·n + 1. A59993

a(n) = floor(n*φ¹¹), where φ is the golden ratio, A001622. A4926

Concentric 18-gonal numbers. A195147

Number A(n,k) of partitions of kⁿ into parts that are at most n with at least one part of each size; square array A(n,k), n>=0, k>=0, read by antidiagonals. A238012