Properties of the Number 1687

One Thousand Six Hundred Eighty-Seven

Basics

Value: 1686 → 1687 → 1688

Parity: odd

Prime: No

Previous Prime: 1669

Next Prime: 1693

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 7 × 241

Divisors: 1, 7, 241, 1687

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11010010111

Octal: 3227

Duodecimal: B87

Hexadecimal: 697

Square: 2845969

Square Root: 41.0731055558257

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

G.f.: ∏_k>=1 (1 + x^{2·k - 1}) / (1 - x^2·k). A6950

Number of non-condensed integer partitions of n, or partitions where it is not possible to choose a different divisor of each part. A370320

Number of orderless same-trees of weight n. A289078

a(n) = n² + 6. A114949

a(n) = ∑_k=1..n floor(n/k)². A222548

Numbers that when divided by the sum of their digits leave 15 as remainder. A341182

Generalized Stirling number triangle of first kind read by rows: T(n, k) = [x^k] ∏_m=1..n (x - m - r), with r = 5. A51338

G.f.: ∏_k>0 (1-x^2k-1)/(1-x^2k). A106507

Table in which the g.f. of row n, R(n,x), satisfies ∑_k=-oo..+oo (x^k - n·R(n,x))^k = 1 - (n-2)*∑_k>=1 x^k², for n >= 1, as read by antidiagonals. A370030

Analog of A121805, but starting with 4. A366492