Properties of the Number -806

Eight Hundred Six

Basics

Value: -807 → -806 → -805

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 2 × 13 × 31

Divisors: 1, 2, 13, 26, 31, 62, 403, 806

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -1100100110

Octal: -1446

Duodecimal: -572

Hexadecimal: -326

Square: 649636

Square Root: 28.39013913315678

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) = ∑_k=1..n floor(n/k) * (-4)^k-1. A344819

Reflected tetranacci numbers A073817. A74058

Square array A(n,k), n >= 1, k >= 0, read by antidiagonals downwards, where A(n,k) = ∑_j=1..n floor(n/j) * (-k)^j-1. A344824

Expansion of f(-x)³ * f(-x²) * χ(-x³)³ in powers of·where χ(), f() are Ramanujan θ functions. A280328

Triangle read by rows: T(n,k) = T(n-k,k-1) - 2·T(n-k,k) + T(n-k,k+1) with T(0,0) = 1 for 0 <= k <= A003056(n). A291940

Coefficients of modular function G₃(τ). A5761

Determinants of 2 X 2 matrices of non-overlapping blocks of 4 consecutive primes. A117027

Logarithmic derivative of the q-exponential of x, E_q(x,q), evaluated at q=-x. A198262

Expansion of ∏_k>=1 (1 - x^k)^A000593(k). A316366

Sum of totient function: a(n) = ∑_k=1..n φ(k), cf. A000010. A2088