Properties of the Number 31818

Thirty-One Thousand Eight Hundred Eighteen

Basics

Value: 31817 → 31818 → 31819

Parity: even

Prime: No

Previous Prime: 31817

Next Prime: 31847

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 2 × 3 × 5303

Divisors: 1, 2, 3, 6, 5303, 10606, 15909, 31818

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 111110001001010

Octal: 76112

Duodecimal: 164B6

Hexadecimal: 7c4a

Square: 1012385124

Square Root: 178.37600735524944

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

T(n,k)=Number of nXk arrays containing k copies of 0..n-1 with every element equal to at least one vertical or antidiagonal neighbor and the top left element equal to 0. A268159

Square array T(n,k), n>=0, k>=0, read by antidiagonals downwards, where column k is the expansion of 1/(1 - 9·x*(1 + x)^k)^1/3. A361839

Expansion of (1 - x)² * ∑_j>=0 (x^j / (1 - ∑_k=1..j x^k)). A369116

Number of 4Xn arrays containing n copies of 0..4-1 with every element equal to at least one vertical or antidiagonal neighbor and the top left element equal to 0. A268161

T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with no 2X2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements. A251128

Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 50 ones. A31818