Properties of the Number 81980

Eighty-One Thousand Nine Hundred Eighty

Basics

Value: 81979 → 81980 → 81981

Parity: even

Prime: No

Previous Prime: 81973

Next Prime: 82003

Digit Sum: 26

Digital Root: 8

Palindrome: No

Factorization: 2 ² × 5 × 4099

Divisors: 1, 2, 4, 5, 10, 20, 4099, 8198, 16396, 20495

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

5184 Try Today's Challenge

Representations

Binary: 10100000000111100

Octal: 240074

Duodecimal: 3B538

Hexadecimal: 1403c

Square: 6720720400

Square Root: 286.3214976211182

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

Number of edges among all distinct circles that can be constructed from an n·n square grid of points using only a compass. A359934

a(n) = numerator of the sum of the reciprocals of the n primes from prime(n(n-1)/2+1) to prime(n(n+1)/2). A81980