Properties of the Number -680

Six Hundred Eighty

Basics

Value: -681 → -680 → -679

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 2 ³ × 5 × 17

Divisors: 1, 2, 4, 5, 8, 10, 17, 20, 34, 40

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: Yes

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Representations

Binary: -1010101000

Octal: -1250

Duodecimal: -488

Hexadecimal: -2a8

Square: 462400

Square Root: 26.076809620810597

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

Riordan array (1/(1+x), x/(1+x)²), inverse array is A039599. A129818

Dirichlet inverse of sigma₂ function (A001157). A53822

Riordan array (1/(1+x)³,x/(1+x)²). A109954

a(n) = ∑_k=0..n (-1)^n-k*k·Stirling2(n,k). A101851

Inverse of twin-prime related triangle A111125. A113187

Expansion of ∏_k>=1 theta₄(x^k), where theta₄() is the Jacobi θ function. A320908

Expansion of Product (1 - x^k)¹⁰ in powers of x. A10818

Triangle of coefficients of characteristic polynomial of M_n, the n X n matrix M_i,j = min(i,j). A76756

Expansion of theta₄(q)²*theta₄(q²)⁴ in powers of q. A120030

Expansion of r(q⁴) / r(q)⁴ in powers of q where r() is the Rogers-Ramanujan continued fraction. A285584