Properties of the Number 11820

Eleven Thousand Eight Hundred Twenty

Basics

Value: 11819 → 11820 → 11821

Parity: even

Prime: No

Previous Prime: 11813

Next Prime: 11821

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 2 ² × 3 × 5 × 197

Divisors: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 10111000101100

Octal: 27054

Duodecimal: 6A10

Hexadecimal: 2e2c

Square: 139712400

Square Root: 108.71982339941506

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

G.f.: ∏_{n >= 0} (1+x²ⁿ⁺¹)/(1-x²ⁿ⁺¹). A80054

3 times heptagonal numbers: a(n) = 3·n*(5·n-3)/2. A152773

Expansion of φ(q²) / φ(-q) in powers of q where φ() is a Ramanujan θ function. A208850

Expansion of theta₃(q) / theta₃(q²) in powers of q. A80015

Expansion of f(-q) / f(q) in powers of q where f() is a Ramanujan θ function. A108494

a(1) = 1, a(2) = 5, a(n+2) = 5·a(n+1) + (n + 1)²*a(n). A142980

a(n) = Pell(n)*A008653(n) for n>=1, with a(0)=1, where A008653 is the θ series of direct sum of 2 copies of hexagonal lattice. A209447

Expansion of φ(-q) / φ(q²) in powers of q where φ() is a Ramanujan θ function. A210030

A triangle related to the GF(z) formulas of the rows of the ED4 array A167584. A167594

G.f.: ∑_n>=0 ( (1+x)ⁿ - 1 )ⁿ * 2ⁿ / (3 - 2*(1+x)ⁿ)ⁿ⁺¹. A317662