Properties of the Number 1691

One Thousand Six Hundred Ninety-One

Basics

Value: 1690 → 1691 → 1692

Parity: odd

Prime: No

Previous Prime: 1669

Next Prime: 1693

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 19 × 89

Divisors: 1, 19, 89, 1691

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11010011011

Octal: 3233

Duodecimal: B8B

Hexadecimal: 69b

Square: 2859481

Square Root: 41.12177038990418

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

Number of rucksack partitions of n: every consecutive constant subsequence has a different sum. A353864

Generalized 11-gonal (or hendecagonal) numbers: m*(9·m - 7)/2 with m = 0, 1, -1, 2, -2, 3, -3, ... A195160

Number of integer partitions of n whose distinct parts are pairwise indivisible. A305148

Number of integer partitions of n whose first differences (assuming the last part is zero) are unimodal. A332283

Mountain numbers. A134941

Strobogrammatic numbers: the same upside down. A787

a(n) = floor(n*φ⁸), where φ is the golden ratio, A001622. A4923

Numbers that are the sum of 3 nonzero squares in exactly 10 ways. A25330

Composite numbers whose divisors (except 1) all contain the digit 9. A62680

Number of compositions (ordered partitions) of n into distinct parts >= 2. A32022