Properties of the Number 19904

Nineteen Thousand Nine Hundred Four

Basics

Value: 19903 → 19904 → 19905

Parity: even

Prime: No

Previous Prime: 19891

Next Prime: 19913

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 2 ⁶ × 311

Divisors: 1, 2, 4, 8, 16, 32, 64, 311, 622, 1244

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100110111000000

Octal: 46700

Duodecimal: B628

Hexadecimal: 4dc0

Square: 396169216

Square Root: 141.08153670838718

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)=Equals one maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal and antidiagonal neighbors in a random 0..1 nXk array. A220579

T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. A303084

T(n,k)=Number of (n+2)X(k+2) binary arrays with 3X3 subblock sums nondecreasing rightwards and downwards. A186840

Numbers k such that the decimal number concat(4,k) is a square. A273359

Record-breaking values, for increasing positive integers k == 1 or 5 mod 6, of the conjectured length of the longest primitive cycle(s) of positive integers under iteration by the Collatz-like 3x+k function. A226670

Expansion of (φ(q⁴) / φ(q))² in powers of q where φ() is a Ramanujan θ function. A260186

E.g.f. satisfies A(x) = -log(1 - x·exp(A(x))) * exp(A(x)). A357343

Numbers k such that 87·2^k+1 is prime. A32393

Number of (n+2)X4 binary arrays with 3X3 subblock sums nondecreasing rightwards and downwards. A186833

Equals one maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal and antidiagonal neighbors in a random 0..1 2Xn array. A220580