Properties of the Number 15813

Fifteen Thousand Eight Hundred Thirteen

Basics

Value: 15812 → 15813 → 15814

Parity: odd

Prime: No

Previous Prime: 15809

Next Prime: 15817

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 7 × 251

Divisors: 1, 3, 7, 9, 21, 63, 251, 753, 1757, 2259

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 11110111000101

Octal: 36705

Duodecimal: 9199

Hexadecimal: 3dc5

Square: 250050969

Square Root: 125.74975149080812

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

Let p = n-th prime == 7 mod 8; a(n) = sum of quadratic residues mod p that are < p/2. A282039

Triangle read by rows: T(n,k) = number of peakless Motzkin paths of length n containing k subwords of the type uh^ju, dH^jd, or dh^ju for some j>0, where u=(1,1), d=(1,-1) and h=(1,0) (can be easily expressed using RNA secondary structure terminology). A98056

Numbers k such that there is a number m < k satisfying A000203(k) = A000203(m) = m + k - gcd(m,k). A124141

Numbers k such that 6!*(2·k-7)!/(k!*(k-1)!) is an integer. A4786

Number of n X n arrays of squares of integers summing to 4 with every element equal to at least one neighbor. A146089

Numbers k such that 7!*(2k-8)!/(k!*(k-1)!) is an integer. A4787

Squares visited by a knight moving on a square-spiral numbered board where the knight moves to the smallest numbered unvisited square and where the square number is more than the number of currently visited squares. A358150

Inverse of 1804th cyclotomic polynomial. A15813

Number of (n+2)X(4+2) 0..1 arrays with no 3x3 subblock diagonal sum less than the antidiagonal sum or central row sum equal to the central column sum. A258541

Number of (n+2)X(6+2) 0..1 arrays with no 3x3 subblock diagonal sum less than the antidiagonal sum or central row sum equal to the central column sum. A258543