Properties of the Number -809

Eight Hundred Nine

Basics

Value: -810 → -809 → -808

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 809

Divisors: 1, 809

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -1100101001

Octal: -1451

Duodecimal: -575

Hexadecimal: -329

Square: 654481

Square Root: 28.442925306655784

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

Values of n such that L(10) and N(10) are both prime, where L(k) = (n²+n+1)*2^2·k + (2·n+1)*2^k + 1, N(k) = (n²+n+1)*2^k + n. A227448

a(n) = ∑_k=0..n-1 3^k*B(k)*C(n,k) where B(k) is the k-th Bernoulli number and C(n,k)=binomial(n,k). A83007

Numerators of column 2 of table described in A051714/A051715. A51718

Numerator of Bernoulli(n, 1/3). A157799

Triangle read by rows T(n, k) = ∑_h>=0 Bernoulli(h)*binomial(n, h)*Stirling2(n-h, k)*k^h for n>=1 and 1<=k<=n. A339208

Expansion of 1 / ∑_{k in Z} x^3·k / (1 - x^5·k+1). A375064

a(n) = -a(n-2) + 2·a(n-4) - a(n-10). A89135

Lesser of twin primes. A1359

Primes of the form x² + xy + 2y², with·and y nonnegative. A106856

Sophie Germain primes p: 2p+1 is also prime. A5384