Properties of the Number -1688

Six Hundred Eighty-Eight

Basics

Value: -1689 → -1688 → -1687

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 2 ³ × 211

Divisors: 1, 2, 4, 8, 211, 422, 844, 1688

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: -11010011000

Octal: -3230

Duodecimal: -B88

Hexadecimal: -698

Square: 2849344

Square Root: 41.08527716834828

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 e.g.f. sin(x/cosh(x)) (odd powers only). A9563

Triangle read by rows: T(n,k) is the k-th generalized Eulerian number of order n and degree 4, n >= 1. A211234

Let b(0)=n, b(1)=n+1, b(2)=n+2, and b(k)=(b(k-3)*b(k-2)*b(k-3)) mod (b(k-3)+b(k-2)+b(k-1)) for k>=3. Continue until either b(k)=0, in which case a(n)=k, or the ordered triple [b(k-2),b(k-1),b(k)] has appeared before, in which case a(n)=-k. If neither of these ever occur, then a(n)=0. A309869

Number of finite connected sets of positive integers greater than one with least common multiple n. A286518

Composite numbers k such that the digits of the prime factors of k are either 1 or 2. A36302

Numbers k whose largest divisor <= sqrt(k) equals 8. A162528

Numbers where 8 outnumbers any other digit. A292458

a(n) = 40·n - 32. A139279

Index of 10ⁿ in A302656, or -1 if 10ⁿ does not appear in A302656. A377906

Where 7ⁿ occurs in n-almost-primes, starting at a(0)=1. A78845