Properties of the Number 1840

One Thousand Eight Hundred Forty

Basics

Value: 1839 → 1840 → 1841

Parity: even

Prime: No

Previous Prime: 1831

Next Prime: 1847

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 2 ⁴ × 5 × 23

Divisors: 1, 2, 4, 5, 8, 10, 16, 20, 23, 40

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 11100110000

Octal: 3460

Duodecimal: 1094

Hexadecimal: 730

Square: 3385600

Square Root: 42.89522117905443

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*(n + 6). A28560

Numerator of 1/9 - 1/n². A61039

Vertex number of a square spiral in which the length of the first two edges are the legs of the primitive Pythagorean triple [3, 4, 5]. The edges of the spiral have length A195019. A195020

Numbers that can be expressed as the difference of the squares of primes in just one distinct way. A90781

a(n) = n*(7·n - 1)/2. A22264

Triangle of polynomial coefficients related to the series expansions of (1-x)^(-1-2·n/2). A161198

Numbers n such that the decimal expansions of both n and n² have 0 as smallest digit and 8 as largest digit. A256708

Numbers of the form n*(7n+-1)/2. A57570

E-toothpick sequence (see Comments lines for definition). A161328

Expansion of ∑_n>=1 ( (1 + xⁿ)ⁿ - 1 ). A318636