Properties of the Number -215

Two Hundred Fifteen

Basics

Value: -216 → -215 → -214

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 8

Digital Root: 8

Palindrome: No

Factorization: 5 × 43

Divisors: 1, 5, 43, 215

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -11010111

Octal: -327

Duodecimal: -15B

Hexadecimal: -d7

Square: 46225

Square Root: 14.66287829861518

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 η(q)⁵ / η(q⁵) in powers of q. A109064

Expansion of the series reversion of x/((1 + x)*(1 - x²)). A291534

Series expansion of the exponential generating function exp(ff6^!(x)) - 1 where ff6^!(x) = x * (1-3·x-x²+x³) / (1+3·x+x²-x³). A383995

Expansion of χ(x) / φ(x²) in powers of·where φ(), χ() are Ramanujan θ functions. A85261

a(1) = 1, then subtract, multiply, and add 2, 3, 4; 5, 6, 7; ... in that order. A362270

a(n) = 1 - n³. A24001

G.f.: x^{(k² + k}/2) / (∏_i=1..k (1 - xⁱ) * ∏_r>=1 (1 + x^r)) with k = 2. A246581

Coefficients in the expansion of 1/([r] + [2r]x + [3r]x² + ...); [ ] = floor, r = 6/5. A279778

a(n) = 1 + ∑_k=2..n (-1)^k * k·a(floor(n/k)). A361982

Coefficients of the '2nd-order' mock θ function μ(q). A6306