Properties of the Number 81821

Eighty-One Thousand Eight Hundred Twenty-One

Basics

Value: 81820 → 81821 → 81822

Parity: odd

Prime: No

Previous Prime: 81817

Next Prime: 81839

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 17 × 4813

Divisors: 1, 17, 4813, 81821

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 10011111110011101

Octal: 237635

Duodecimal: 3B425

Hexadecimal: 13f9d

Square: 6694676041

Square Root: 286.04370295463593

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

Odd numbers n containing 65536 as the highest power of 2 in their Collatz (3x+1) iteration. A247716

Rydberg constant, in inverse meters. A81821

Number of 3 X n arrays containing n copies of 0..3-1 with row sums equal. A268369