Properties of the Number 21608

Twenty-One Thousand Six Hundred Eight

Basics

Value: 21607 → 21608 → 21609

Parity: even

Prime: No

Previous Prime: 21601

Next Prime: 21611

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 2 ³ × 37 × 73

Divisors: 1, 2, 4, 8, 37, 73, 74, 146, 148, 292

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010001101000

Octal: 52150

Duodecimal: 10608

Hexadecimal: 5468

Square: 466905664

Square Root: 146.99659860010368

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

Array read by antidiagonals: T(m,n) is the number of m X n binary arrays with all 1's connected, a path of 1's from upper left corner to lower right corner, and no 1 having more than two 1's adjacent. A391818

Starting from generation 8 add previous and next term yielding generation 9. A48455

Eight times hexagonal numbers: a(n) = 8·n*(2·n-1). A152750

Number of partitions p of n such that (number of numbers of the form 5k + 3 in p) is a part of p. A241552

G.f. A(x) satisfies: A(x) = x + x² * A(x/(1 - 2·x)) / (1 - 2·x). A351028

Numbers k such that τ(k) - τ(k+1) = 1. A68208

Irregular triangular array: row n gives numbers D, each being the discriminant of the minimal polynomial of a quadratic irrational represented by a continued fraction with period an n-tuple of 1s and 3s. A246921

a(0)=1, a(n) = 8·n*(2·n-1). A67239

a(n) = 4*(3·n+1)*(3·n+2). A144410

Number of n X 5 binary arrays with all 1s connected, a path of 1s from upper left corner to lower right corner, and no 1 having more than two 1s adjacent. A163688