Properties of the Number 21803

Twenty-One Thousand Eight Hundred Three

Basics

Value: 21802 → 21803 → 21804

Parity: odd

Prime: Yes

Previous Prime: 21799

Next Prime: 21817

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 21803

Divisors: 1, 21803

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010100101011

Octal: 52453

Duodecimal: 1074B

Hexadecimal: 552b

Square: 475370809

Square Root: 147.65838953476364

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

Father primes of order 11. A136080

The MC polynomials. A163972

T(n,k) = Number of n X k 0..4 arrays with each element·equal to the number of its horizontal and vertical neighbors equal to 2,1,0,3,4 for x=0,1,2,3,4. A196436

T(n,k) = Number of n X k 0..4 arrays with each element·equal to the number of its horizontal and vertical neighbors equal to 4,1,3,2,0 for x=0,1,2,3,4. A197199

Expansion of 1/(x^k*(1-x-2·x^k+1)) for k=4. A143447

a(n) = 10 + floor(∑_j=1..n-1 a(j) / 2). A120138

Primes p such that p - 2², p - 4² and p - 6² are all positive primes. A246873

Expansion of (1 - x + x⁴)/((1 - x + x⁴)² - 4·x⁴). A376718

Number of nX4 0..4 arrays with each element·equal to the number its horizontal and vertical neighbors equal to 2,1,0,3,4 for x=0,1,2,3,4. A196432

Number of n element 0..1 arrays with each element the minimum of 7 adjacent elements of a random 0..1 array of n+6 elements. A217838