Properties of the Number -2181

One Hundred Eighty-One

Basics

Value: -2182 → -2181 → -2180

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 3 × 727

Divisors: 1, 3, 727, 2181

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -100010000101

Octal: -4205

Duodecimal: -1319

Hexadecimal: -885

Square: 4756761

Square Root: 46.70117771534247

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) = n! - n⁷. A196414

a(n) = ∑_k=0..n (-1)^k * binomial(n+3·k+3,n-k) * Catalan(k). A360059

Coordination sequence for "cab" 3D uniform tiling formed from octahedra and truncated cubes. A299266

a(n) = least k such that the remainder of 13^k divided by k is n. A127821

Numbers k such that k, k+1 and k+2 are products of two primes. A56809

Numbers k such that k, k+1 and k+2 have the same number of divisors. A5238

Smallest of three consecutive squarefree numbers k, k+1, k+2 of the form p·q where p and q are distinct primes. A39833

Toothpick sequence on hexagonal net. A182840

a(n) = 2·n² + 3. A93328

Trajectory of 40 under the map n-> A006369(n). A217729