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Properties of the Number 18189

Eighteen Thousand One Hundred Eighty-Nine

Basics

Value: 18188 → 18189 → 18190

Parity: odd

Prime: No

Previous Prime: 18181

Next Prime: 18191

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 2 × 43 × 47

Divisors: 1, 3, 9, 43, 47, 129, 141, 387, 423, 2021

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 100011100001101

Octal: 43415

Duodecimal: A639

Hexadecimal: 470d

Square: 330839721

Square Root: 134.86660075793412

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

Array read by antidiagonals: T(m,n) is the number of fixed polyominoes that have a width of m and height of n. A292357
T(n,k)=Number of nXk 0..1 arrays with no element equal to more than three of its king-move neighbors and with new values introduced in order 0 sequentially upwards. A281344
Not necessarily symmetric n X 3 crossword puzzle grids. A34184
T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2, 3 or 6 king-move adjacent elements, with upper left element zero. A297993
Odd numbers k that can be factored to such a pair of coprime factors·and y that A347381(k) < min(A347381(x), A347381(y)). A347390
Denominators of continued fraction convergents to sqrt(449). A41855
Irregular triangular array T; row n shows the coefficients of the (n-1)-st polynomial in the obverse convolution s(x)**t(x), where s(x) = n2 x and t(x) = 2x+1. See Comments. A375042
Lucky numbers that are the sum of the first k primes for some k. A46286
Terms of A007504 divisible by 3. A249679
Number of nX4 0..1 arrays with no element equal to more than three of its king-move neighbors and with new values introduced in order 0 sequentially upwards. A281340