Properties of the Number 21444

Twenty-One Thousand Four Hundred Forty-Four

Basics

Value: 21443 → 21444 → 21445

Parity: even

Prime: No

Previous Prime: 21433

Next Prime: 21467

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 2 ² × 3 × 1787

Divisors: 1, 2, 3, 4, 6, 12, 1787, 3574, 5361, 7148

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001111000100

Octal: 51704

Duodecimal: 104B0

Hexadecimal: 53c4

Square: 459845136

Square Root: 146.43770006388382

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

a(n) = coefficient of xⁿ in A(x) such that: 1 = ∑_n=-oo..+oo xⁿ * (A(x) - x^4·n+3)^n-1. A358963

Number of steps needed to reach position "YZ^n-1" in the Towers of Hanoi exchanging disks puzzle with 3 pegs and n disks. A341580

Decimal expansion of 58291/21444. A368653

Decimal expansion of 158452/21444. A368654

a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (odd natural numbers), t = (primes). A25117

Number of right triangles on a (n+1) X 4 grid. A189808

1-sequence of reduction of (3n-2) by x² -> x+1. A192312

Decimal expansion of 1/440. A21444

Numbers n such that the sum of the non-anti-divisors of n is a multiple of the sum of the anti-divisors of n. A245649

Number of (n+2)X4 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly two ways, and new values 0..1 introduced in row major order. A206653