Properties of the Number -1918

Nine Hundred Eighteen

Basics

Value: -1919 → -1918 → -1917

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 × 7 × 137

Divisors: 1, 2, 7, 14, 137, 274, 959, 1918

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: Yes

Tetrahedral: No

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Representations

Binary: -11101111110

Octal: -3576

Duodecimal: -113A

Hexadecimal: -77e

Square: 3678724

Square Root: 43.79497688091638

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) = -2·n² + 12·n - 14. A147973

Expansion of (ψ(x) * φ(-x)⁴)² in powers of·where φ(), ψ() are Ramanujan θ functions. A215472

Expansion of (∏_k>0 theta₄(q^k)/theta₃(q^k))^1/2, where theta₃() and theta₄() are the Jacobi θ functions. A320992

Triangle read by rows, T(n,k) = (-1)^k*{{n,k}} where {{n,k}} are the second-order Stirling set numbers, n>=0, 0<=k<=n/2. A137375

Weight 5 level 11 cusp form with complex multiplication by Q(sqrt(11)) and trivial character. A65099

Expansion of (ψ(-x) * φ(x)⁴)² in powers of·where φ(), ψ() are Ramanujan θ functions. A209942

Numerator of Hermite(n, 1/31). A160299

Coefficients in the expansion of ([s] + [2s]x + [3s]x² + ...)/([r] + [2r]x + [3r]x² + ...); [ ] = floor, r = sqrt(2), s = r/(1-r). A279631

Heptagonal numbers (or 7-gonal numbers): n*(5·n-3)/2. A566

Regular triangle read rows: T(n,k) = number of non-isomorphic multiset partitions of size n and length k. A317533