Properties of the Number 20863

Twenty Thousand Eight Hundred Sixty-Three

Basics

Value: 20862 → 20863 → 20864

Parity: odd

Prime: No

Previous Prime: 20857

Next Prime: 20873

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 31 × 673

Divisors: 1, 31, 673, 20863

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000101111111

Octal: 50577

Duodecimal: 100A7

Hexadecimal: 517f

Square: 435264769

Square Root: 144.44029908581606

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

The number of edges formed on an isosceles triangle by straight line segments mutually connecting all vertices and all points that divide the two equal length sides into n equal parts; the base of the triangle contains no points other than its vertices. A333027

Expansion of (3 + x²) / (1 - x)⁴. A37237

Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any element within a city block distance of two, and containing the value n(n+1)/2-2. A212039

a(n) = number of triples (a,b,c) of natural numbers a,b,c <= n with gcd(a,b)=gcd(b,c)=gcd(c,a)=1. A256390

Indices of primes in sequence defined by A(0) = 73, A(n) = 10·A(n-1) - 17 for n > 0. A101131

Number of nXnXn 0..6 triangular arrays with each element·equal to the number its neighbors equal to 6,2,1,0,0,0,1 for x=0,1,2,3,4,5,6. A203220

Decimal expansion of log₂(11). A20863

Square array T(n,k) read by antidiagonals upwards: "Dropping Times" in reduced Collatz sequences. (See "Comments" for definitions and explanation.) A259663

Number of set partitions of [n] such that for each block b the smallest integer interval containing b has at most seven elements. A276723

G.f. A(x) satisfies: A( A(x)² - A(x)³ ) = x·A(x). A268655