Properties of the Number 90018

Ninety Thousand Eighteen

Basics

Value: 90017 → 90018 → 90019

Parity: even

Prime: No

Previous Prime: 90017

Next Prime: 90019

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 × 3 ³ × 1667

Divisors: 1, 2, 3, 6, 9, 18, 27, 54, 1667, 3334

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 10101111110100010

Octal: 257642

Duodecimal: 44116

Hexadecimal: 15fa2

Square: 8103240324

Square Root: 300.02999850015

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

Smallest m such that A259043(m) = n. A259046

G.f.: 1 = ∑_n>=0 a(n)*xⁿ*(1-x)ⁿ⁺¹/(1 + (n+1)*x)^2·n+1. A210097

Number of n X 1 0..2 arrays with all rows and columns having a nonnegative second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative. A223188

Numbers n such that A = n - digitsum(n) is divisible by the largest power of 10 <= A. A242474

Coefficients of expansion of 1/sqrt(1 - 10·x + 9·x²); also, a(n) is the central coefficient of (1 + 5·x + 4·x²)ⁿ. A84771

Product of two successive Catalan numbers C(n)*C(n+1). A5568

a(n) = C(floor(n/2 + 1/2))*C(floor(n/2 + 1)) where C(i) = Catalan numbers A000108. A5817

a(n) = 6·a(n-1) + 3·a(n-2) for n > 2, a(0)=1, a(1)=6. A90018

T(n,k)=Number of nXk 0..2 arrays with all rows and columns having a nonnegative second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative. A223195

Number of rooted polyhedral graphs with n edges. A287