Properties of the Number 21224

Twenty-One Thousand Two Hundred Twenty-Four

Basics

Value: 21223 → 21224 → 21225

Parity: even

Prime: No

Previous Prime: 21221

Next Prime: 21227

Digit Sum: 11

Digital Root: 2

Palindrome: No

Factorization: 2 ³ × 7 × 379

Divisors: 1, 2, 4, 7, 8, 14, 28, 56, 379, 758

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001011101000

Octal: 51350

Duodecimal: 10348

Hexadecimal: 52e8

Square: 450458176

Square Root: 145.6845908117945

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

Numbers that are the sum of 9 positive 9th powers. A3398

Absolute discriminants of complex quadratic fields with 3-class group of elementary abelian type (3,3) of rank 2. A242863

Absolute discriminants of complex quadratic fields with 3-class rank 2. A242862

T(n,k)=Number of nXk 0..2 arrays with exactly floor(nXk/2) elements unequal to at least one king-move neighbor, with new values introduced in row major 0..2 order. A222402

T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2 or 4 horizontally or vertically adjacent elements, with upper left element zero. A301669

Absolute discriminants of complex quadratic fields with 3-class group of type (3,3) and Hilbert 3-class field tower of exact length 2. A242864

Consider the tiling of the plane with squares of two different sizes as in Fig. 2.4.2(g) of Grünbaum and Shephard, p. 74. a(n) is the number of connected figures that can be formed on this tiling, from any n squares. A121197

Triangle T(n,k), n >= 2, 0 <= k <= floor(n²/2)-2·n+2, read by rows, where T(n,k) is the number of 2*(k+2·n-2)-cycles in the n X n grid graph which pass through NW and SE corners ((0,0),(n-1,n-1)). A333667

Place two n-gons with radii 1 and 2 concentrically, forming an annular area between them. Connect all the vertices with line segments that lie entirely within that area. Then a(n) is the number of regions in that figure. A337700

a(n) = T(5,n), array T given by A048505. A48510