Properties of the Number 19818

Nineteen Thousand Eight Hundred Eighteen

Basics

Value: 19817 → 19818 → 19819

Parity: even

Prime: No

Previous Prime: 19813

Next Prime: 19819

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 2 × 3 ³ × 367

Divisors: 1, 2, 3, 6, 9, 18, 27, 54, 367, 734

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100110101101010

Octal: 46552

Duodecimal: B576

Hexadecimal: 4d6a

Square: 392753124

Square Root: 140.7764184798008

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

Main diagonal of array in A358304, divided by 2. A358307

The sum of the first n terms of the sequence is the concatenation of the first n digits of the sequence, and a(1) = 2. A299865

Number of partitions of n into parts not of the form 13k, 13k+5 or 13k-5. Also number of partitions with at most 4 parts of size 1 and differences between parts at distance 5 are greater than 1. A35953

a(n) is the smallest number d if the point (d,d) is shared by exactly n different Dyck paths in the main diagonal of the diagram of the symmetries of σ described in A237593. A282197

Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-2)*b(n-1)*b(n), where a(0) = 1, a(1) = 2, b(0) = 3, b(1) = 4, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences. A296278

Numbers n such that n² + 1 is divisible by a 5th power. A218564

Expansion of ∑_i>=0 x^2ⁱ/(1 - x^2ⁱ) / ∏_j>=0 (1 - x^{2^j}). A281688

Expansion of ∑_1<=i<=j<=k q^i+j+k/( (1-qⁱ)*(1-q^j)*(1-q^k) )². A374930

Number of ways to place 7 nonattacking amazons (superqueens) on a 7 X n board. A174646

Expansion of φ(-x⁵) * f(x², x⁸) / ψ(-x)² in powers of·where φ, ψ, f(,) are Ramanujan θ functions. A259392