Properties of the Number -2121

One Hundred Twenty-One

Basics

Value: -2122 → -2121 → -2120

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 6

Digital Root: 6

Palindrome: No

Factorization: 3 × 7 × 101

Divisors: 1, 3, 7, 21, 101, 303, 707, 2121

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -100001001001

Octal: -4111

Duodecimal: -1289

Hexadecimal: -849

Square: 4498641

Square Root: 46.05431575867782

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

Expansion of ψ(q³) / ψ(q)³ in powers of q where ψ() is a Ramanujan θ function. A132979

Expansion of q^-1 * ψ(-q) / ψ(-q³)³ in powers of q where ψ() is a Ramanujan θ function. A133637

Expansion of q^-1 * ψ(q) / ψ(q³)³ in powers of q where ψ() is a Ramanujan θ function. A258093

Alternating sum of heptagonal numbers. A266085

∏_n>=1 (1 + xⁿ)^a(n) = 1 + ∑_n>=1 φ(n) * xⁿ, where φ = A000010. A328774

Numbers that contain only 1's and 2's. Nonempty binary strings of length n in lexicographic order. A7931

Doublets: base-10 representation is the juxtaposition of two identical strings. A20338

Generalized 12-gonal numbers: k*(5·k-4) for k = 0, +-1, +-2, ... A195162

12-gonal (or dodecagonal) numbers: a(n) = n*(5·n-4). A51624

Number of points of norm <= n² in square lattice. A328