Properties of the Number 40391

Forty Thousand Three Hundred Ninety-One

Basics

Value: 40390 → 40391 → 40392

Parity: odd

Prime: No

Previous Prime: 40387

Next Prime: 40423

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 13 ² × 239

Divisors: 1, 13, 169, 239, 3107, 40391

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 1001110111000111

Octal: 116707

Duodecimal: 1B45B

Hexadecimal: 9dc7

Square: 1631432881

Square Root: 200.97512283862397

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)² is a triangular number: a(n) = 6·a(n-1) - a(n-2) with a(0)=0, a(1)=1. A1109

Numbers that are the sum of 5 positive 9th powers. A3394

Indices of square numbers that are also hexagonal. A46176

Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) is Chebyshev polynomial of the second kind U_n(x), evaluated at x=k. A323182

Numerators of the continued fraction n-1/(n-1/...) [n times]. A97690

Denominators of continued fraction convergents to sqrt(8). A41011

Square roots of [A055872/8]: Their square written in base 8, with some digit appended, is again a square. A204512

a(n) = 64·n⁶ - 80·n⁴ + 24·n² - 1. A242851

a(n) = (2·Pell(n+1) - (1+(-1)ⁿ))/4. A105635

a(n) = U(2·n, n), where U(n, x) is the Chebyshev polynomial of the second kind. A349073