Properties of the Number 19726

Nineteen Thousand Seven Hundred Twenty-Six

Basics

Value: 19725 → 19726 → 19727

Parity: even

Prime: No

Previous Prime: 19717

Next Prime: 19727

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 2 × 7 × 1409

Divisors: 1, 2, 7, 14, 1409, 2818, 9863, 19726

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100110100001110

Octal: 46416

Duodecimal: B4BA

Hexadecimal: 4d0e

Square: 389115076

Square Root: 140.44927910103348

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

Number T(n,k) of equivalence classes of ways of placing k 8 X 8 tiles in an n X n square under all symmetry operations of the square; irregular triangle T(n,k), n>=8, 0<=k<=floor(n/8)², read by rows. A236915

Squarefree n such that the elliptic curve n·y² = x³ - x arising in the "congruent number" problem has rank 3. A62693

G.f.: A(x) = 1 + x·A(x)*A(-x) + x²*exp( ∑_n>=1 2·L(n)²*x^2·n/n ), where A(x) = exp(∑_n>=1 L(n)*xⁿ/n). A205566

Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum 1 3 6 or 8 and every diagonal and antidiagonal sum not 1 3 6 or 8. A252008

Let sequence B_n={b_m} be defined by: b₁=prime(n), b₂=prime(n+1); for m>=3, b_m=b_m-2+b_m-1 if b_m-2+b_m-1 is not semiprime, otherwise b_m is the least prime divisor of b_m-2+b_m-1. Then a(n) is the maximal term of sequence B_n, or a(n)=0 if B_n is unbounded. A221218

Decimal expansion of sqrt(π)/24. A19726

Number of (3+1) X (n+1) arrays of permutations of 0..n·4+3 with each element having directed index change 0,1 2,2 1,0 -1,2 -2,-1 or -1,-1. A264424

Number of nX6 0..1 arrays with every element unequal to 0, 1, 2, 3, 7 or 8 king-move adjacent elements, with upper left element zero. A316516