Properties of the Number 19280

Nineteen Thousand Two Hundred Eighty

Basics

Value: 19279 → 19280 → 19281

Parity: even

Prime: No

Previous Prime: 19273

Next Prime: 19289

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 2 ⁴ × 5 × 241

Divisors: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 100101101010000

Octal: 45520

Duodecimal: B1A8

Hexadecimal: 4b50

Square: 371718400

Square Root: 138.85243966167826

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 locally disjoint rooted identity trees with n nodes, meaning no branch overlaps any other branch of the same root. A316471

a(n) = ceiling(∑_i=1..n-1 a(i)/4) for n >= 2 starting with a(1) = 1. A120160

a(n) = (3·n⁴ - 4·n³ + n² + 4·n + 4)/4. A366478

Number of distinct edges among all circles that can be constructed on vertices of an n-sided regular polygon, using only a compass. A359047

Triangle read by rows: T(n,k) = number of rooted maps with n edges on a nonorientable surface of genus k (1 <= k <= n). A267180

a(n) = (2·n⁴ - 6*(-1)ⁿ*n² - 2·n² + 3*(-1)ⁿ - 3)/96. A350050

Truncate Stirling's asymptotic series for 4! after n terms and round to the nearest integer. A362116

Number of rooted maps with n edges on Klein bottle. A6344

Expansion of (1 - sqrt( 1 - 4·x*sqrt( 1 + 4·x )) )/( 2·x ). A81698

a(n) = ∑_{k=0..floor(n/2)} T(n-k,k), T given by A026725. A26735