Properties of the Number 18220

Eighteen Thousand Two Hundred Twenty

Basics

Value: 18219 → 18220 → 18221

Parity: even

Prime: No

Previous Prime: 18217

Next Prime: 18223

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 2 ² × 5 × 911

Divisors: 1, 2, 4, 5, 10, 20, 911, 1822, 3644, 4555

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100011100101100

Octal: 43454

Duodecimal: A664

Hexadecimal: 472c

Square: 331968400

Square Root: 134.98148021117564

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 T(n,k) of tilings of a 5 X n rectangle with pentominoes of any shape and exactly k pentominoes of shape P; triangle T(n,k), n>=0, 0<=k<=n, read by rows. A247706

Numbers k such that k³ has only even digits. A52004

Number of 2 X 2 matrices having all elements in {-n,...n} and determinant 4. A209988

Irregular table read by rows: Take a diagonal-edged (or diamond-shaped) checkerboard with all diagonals drawn, as in A333434. Then T(n,k) = number of k-sided polygons in that figure for k >= 3. A333458

a(1)=1, a(n)=a(n-1)+n³ if n odd, a(n)=a(n-1)+ n⁴ if n is even. A140155

a(n) = 25·n² - 5. A158446

Coordination sequence for α-Mn, Position Mn3. A9952

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

Numbers m such that each of p=6·m+1, q=6·p+1, r=6·q+1 and s=6·r+1 is prime. A263311

Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A082351/A082352. A89424