Properties of the Number 31806

Thirty-One Thousand Eight Hundred Six

Basics

Value: 31805 → 31806 → 31807

Parity: even

Prime: No

Previous Prime: 31799

Next Prime: 31817

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 × 3 ³ × 19 × 31

Divisors: 1, 2, 3, 6, 9, 18, 19, 27, 31, 38

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 111110000111110

Octal: 76076

Duodecimal: 164A6

Hexadecimal: 7c3e

Square: 1011621636

Square Root: 178.3423673724222

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

Triangle T(n, k) = [x^k](p(x, n, q)) where p(x,n,q) = ∏_j=1..n (x + q^j) + ∏_j=1..n (x·q^j + 1), p(x, 0, q) = 1, and q = 2, read by rows. A173048

Number of ZnS polytypes that repeat after n layers. A11957

Integers k equal to the sum over A000203(t) mod t, for some steps, starting with t = k and then using the result to feed the next calculation. A377001

Number of (7+1) X (n+1) 0..1 arrays with every 2 X 2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically. A258560

Records in A171898. A309813

T(n,k)=S(2n+2,n-1,k-1), 0<=k<=n, n >= 0, array S as in A050157. A50162

Number of multi-directed animals on the square lattice. A59713

T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with every 2X2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically. A258554

G.f. A(x) satisfies A(x) = 1 + x·A(x)³ * (1 + 2·A(x)). A336539

Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 38 ones. A31806