Properties of the Number 20221

Twenty Thousand Two Hundred Twenty-One

Basics

Value: 20220 → 20221 → 20222

Parity: odd

Prime: No

Previous Prime: 20219

Next Prime: 20231

Digit Sum: 7

Digital Root: 7

Palindrome: No

Factorization: 73 × 277

Divisors: 1, 73, 277, 20221

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 100111011111101

Octal: 47375

Duodecimal: B851

Hexadecimal: 4efd

Square: 408888841

Square Root: 142.20056258679148

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 regions in a regular 2n-gon when all vertices are connect by straight lines except for the n lines joining diametrically opposite vertices. A368813

Irregular triangle read by rows: T(n,k) is the number of free polyominoes with n cells having k regions between the polyominoes and their bounding boxes, n >= 1, k >= 0. A380282

Numbers k such that 39·2^k + 1 is prime. A2269

Numbers that require three steps to collapse to a single digit in base 4 (written in base 4). A253953

Ternary emirpimes. A119684

Number of n-node unlabeled rooted trees with thinning limbs and root outdegree (branching factor) 9. A244710

Triangle read by rows: T(n,k) is the coefficient A_k in the transformation of 1 + x + x² + ... + xⁿ to the polynomial A_k*(x+3k)^k for 0 <= k <= n. A248977

Expansion of e.g.f. exp(-x·sqrt(1-4·x)). A362161

n written in fractional base 4/2. A24630

Numbers n with the property that n² contains a sequence of four or more consecutive 8's. A301938