Properties of the Number 81740

Eighty-One Thousand Seven Hundred Forty

Basics

Value: 81739 → 81740 → 81741

Parity: even

Prime: No

Previous Prime: 81737

Next Prime: 81749

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 2 ² × 5 × 61 × 67

Divisors: 1, 2, 4, 5, 10, 20, 61, 67, 122, 134

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011111101001100

Octal: 237514

Duodecimal: 3B378

Hexadecimal: 13f4c

Square: 6681427600

Square Root: 285.9020811396797

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, σ(k)) lies on a circle with integral radius centered at the origin, i.e., k² + σ(k)² is a square. A66764

a(n) = ∑_k=0..2n (k+1) * A027052(n, k). A27075

11-level labeled rooted trees with n leaves. A81740