Properties of the Number 20816

Twenty Thousand Eight Hundred Sixteen

Basics

Value: 20815 → 20816 → 20817

Parity: even

Prime: No

Previous Prime: 20809

Next Prime: 20849

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 2 ⁴ × 1301

Divisors: 1, 2, 4, 8, 16, 1301, 2602, 5204, 10408, 20816

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

8509 Try Today's Challenge

Representations

Binary: 101000101010000

Octal: 50520

Duodecimal: 10068

Hexadecimal: 5150

Square: 433305856

Square Root: 144.27751037497146

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)=Number of length n+3 0..k arrays with no disjoint pairs in any consecutive four terms having the same sum. A247726

T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with every 2X2 subblock having the sum of the squares of all six edge and diagonal differences equal to 11 (11 maximizes T(1,1)). A233792

Number of partitions of n into deficient numbers. A97797

Numbers k such that k and k + 1 are both of the form p·q⁴ where p and q are distinct primes. A215197

a(n) = sum of squares of first n positive integers congruent to 1 mod 4. A24381

Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 443", based on the 5-celled von Neumann neighborhood. A282259

a(n) = ∑_{k=0..floor(n/4)} binomial(n+3,4·k+3) * Catalan(k). A360046

Numbers k such that both k and k+1 are not exponentially squarefree numbers. A342188

Numbers k such that 6^k + k⁶ + 1 is prime. A243934

Numbers k such that k and k+1 both have the same number of squarefree divisors and powerful divisors. A360904