Properties of the Number -391

Three Hundred Ninety-One

Basics

Value: -392 → -391 → -390

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 17 × 23

Divisors: 1, 17, 23, 391

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -110000111

Octal: -607

Duodecimal: -287

Hexadecimal: -187

Square: 152881

Square Root: 19.77371993328519

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 exp( ∑_{n >= 1} A188458(n)*xⁿ/n ). A188514

Reversion of Jacobsthal numbers A001045. A91593

Square array T(n,k), n>=0, k>=0, read by antidiagonals, where T(0,k) = 1 and T(n,k) = (1/n) * ∑_j=1..n (-2)^n-j * binomial(n,j) * binomial(n+(k-1)*j,j-1) for n > 0. A336709

Expansion of q^-3/8* η(q)⁷* η(q⁴)²/ η(q²)³ in powers of q. A128713

Square array T(n,k), n>=0, k>=0, read by antidiagonals, where T(0,k) = 1 and T(n,k) = (1/n) * ∑_j=1..n (-k)^n-j * binomial(n,j) * binomial(n,j-1) for n > 0. A336727

Expansion of (1-x)^-1/(1+2·x-x²+x³). A77922

Expansion of (1 + x) / ((1 - x⁴) * (1 + x⁴ - x⁵)) in powers of x. A247918

Expansion of (1 - 2·x²)/(1 + x)⁴. Third column of Riordan triangle A248156. A248159

Expansion of ∑_k>=1 x^k/(1 + k·x^k). A308367

Numerators of the partial alternating sums of the reciprocals of the alternating sum of divisors function (A206369). A379621