Properties of the Number 19900

Nineteen Thousand Nine Hundred

Basics

Value: 19899 → 19900 → 19901

Parity: even

Prime: No

Previous Prime: 19891

Next Prime: 19913

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 ² × 5 ² × 199

Divisors: 1, 2, 4, 5, 10, 20, 25, 50, 100, 199

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: Yes

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100110110111100

Octal: 46674

Duodecimal: B624

Hexadecimal: 4dbc

Square: 396010000

Square Root: 141.06735979665885

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

a(n) = n²*(2·n² - 1); also ∑_k=0..n-1 (2k+1)³. A2593

Transform of n³ by the Riordan array (1/(1-x²), x). A105636

T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the upper median plus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one. A237567

Numbers k such that s(k) = 2·k, where s(k) is the sum of divisors of k that have a square factor (A162296). A322609

The first of three consecutive hexagonal numbers the sum of which is equal to the sum of three consecutive primes. A298272

Triangular numbers whose internal digits form a triangular number. Or triangular number such that deleting the MSD and LSD leaves a triangular number. A77366

Number of unrooted steric quartic trees with 2n (unlabeled) nodes and possessing a bicentroid; number of 2n-carbon alkanes C(2n)H(4n +2) with a bicentroid when stereoisomers are regarded as different. A86200

Triangular numbers that are the product of a square number and a prime number. A253653

The intersection of hexagonal numbers (A000384) and centered 9-gonal numbers (A060544). A272399

Primitive terms of A388034. A388035