Properties of the Number 28780

Twenty-Eight Thousand Seven Hundred Eighty

Basics

Value: 28779 → 28780 → 28781

Parity: even

Prime: No

Previous Prime: 28771

Next Prime: 28789

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 2 ² × 5 × 1439

Divisors: 1, 2, 4, 5, 10, 20, 1439, 2878, 5756, 7195

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 111000001101100

Octal: 70154

Duodecimal: 147A4

Hexadecimal: 706c

Square: 828288400

Square Root: 169.646691685986

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 partitions of n³ into distinct cubes. A30272

Place n equally spaced points on the circumference of a circle of radius r and then connect each pair of points with straight lines whose intersections create A007569(n) - n additional points. Draw a circle of radius r around each of the A007569(n) points. The sequence gives the total number of regions formed from all circle intersections. A374826

a(n) = ∑_i=0..n digsum₈(i)⁴, where digsum₈(i) = A053829(i). A231683

a(n) = ∑_i=0..n digsum₉(i)⁴, where digsum₉(i) = A053830(i). A231687

Number of lines through exactly 3 points of an n X n grid of points. A18810

Numbers k such that σ(k) = σ(k - d(k)). A277273

Numbers whose sum of divisors is equal to the product of the number of divisors of their k first powers, for some k. A283758

Numbers k whose decimal representation, read as a base-18 value and divided by k, yields an integer. A32567

Interprimes which are of the form s·prime, s=20. A75295

Numbers whose natural logarithm, in base 10, starts with 10 distinct digits. A113509