Properties of the Number -686

Six Hundred Eighty-Six

Basics

Value: -687 → -686 → -685

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 20

Digital Root: 2

Palindrome: Yes

Factorization: 2 × 7 ³

Divisors: 1, 2, 7, 14, 49, 98, 343, 686

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -1010101110

Octal: -1256

Duodecimal: -492

Hexadecimal: -2ae

Square: 470596

Square Root: 26.19160170741759

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

Triangle read by rows: coefficients T(n,k) of a binomial decomposition of nⁿ as Sum(k=0..n)T(n,k)*binomial(n,k). A244134

G.f.: Re((i; x)_inf), where (a; q)_inf is the q-Pochhammer symbol, i = sqrt(-1). A278399

Expansion of 1/sqrt(1 - 4·x/(1+x)³). A360133

The main diagonal of the successive differences of A154127. A154570

Expansion of φ(x)² * χ(x²)⁴ * f(-x)² in powers of·where φ(), χ(), f() are Ramanujan θ functions. A280339

Expansion of ∑_k>0 (1/(1+x^k)³ - 1). A363630

Expansion of (1+2x)/sqrt((1-3x²)(1+4x+5x²)). A102882

Numerator of Hermite(n, 3/19). A159620

Totally multiplicative sequence with a(p) = 7*(p-3) for prime p. A167317

Expansions of the characteristic polynomials of certain matrices, see Mathematica code. A136449