Properties of the Number -561

Five Hundred Sixty-One

Basics

Value: -562 → -561 → -560

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 3 × 11 × 17

Divisors: 1, 3, 11, 17, 33, 51, 187, 561

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: Yes

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -1000110001

Octal: -1061

Duodecimal: -3A9

Hexadecimal: -231

Square: 314721

Square Root: 23.68543856465402

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

Alternating sum of squares to n. A89594

Numerators of coefficient array for minimal polynomials of sin(2*π/n). Rising powers of x. A181872

a(n) = -∑_d∣n (-n/d)^d. A76717

a(n) = A000217(n) - A048702(n). A75113

Expansion of ∏_m>=1 (1-m·q^m)²². A22682

Values of n such that L(19) and N(19) 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. A227522

Alternating sum of heptagonal numbers. A266085

G.f. A(x) satisfies: [x^k] (1+x)^n² * A(x) = 0 for k = (n-1)² + 1 through k = n² for n >= 1. A305600

G.f.: A(x,y) = ∑_n=-oo..+oo (-1)ⁿ * (x·y)^n*(n+1/2) * C(x)ⁿ, where C(x) = 1 + x·C(x)² is the g.f. of the Catalan numbers (A000108), as a triangle of coefficients T(n,k) of xⁿ*y^k in A(x,y), read by rows n >= 0. A355344

G.f.: ∑_n=-oo..+oo x^n*(n+1/2) * C(x)^3·n-3, where C(x) = 1 + x·C(x)² is the g.f. of the Catalan numbers (A000108). A355348