Properties of the Number 66821

Sixty-Six Thousand Eight Hundred Twenty-One

Basics

Value: 66820 → 66821 → 66822

Parity: odd

Prime: Yes

Previous Prime: 66809

Next Prime: 66841

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 66821

Divisors: 1, 66821

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 10000010100000101

Octal: 202405

Duodecimal: 32805

Hexadecimal: 10505

Square: 4465046041

Square Root: 258.4975821937219

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

Primes whose base-4 representation also is the base 2-representation of a prime. A235461

Pell equation solutions (8·a(n))² - 65·b(n)² = -1 with b(n):=A097736(n), n >= 0. A97735

Primes equal to a sum of primes with differences congruent to (2,4) mod 6. A104160

a(0) = 2; afterwards a(n) is the least prime greater than a(n-1) such that ω(a(n-1) + a(n)) = n. A357713

Prime numbers of the form 3p+8 where p, p+2 and p+6 are prime numbers. A376013

Lesser of two consecutive primes such that n·p + q is a perfect square, p < q. A64545

SanD-68 primes p: such that p+d is also prime and sum of digits A007953(p(p+d)) = d, with d = 68. A307474

Primes of the form p² +3p + 1, where p is also a prime. A165944

Coefficients of a solution to a functional equation. A92834

Numbers k such that k concatenated with k+8 gives the product of two numbers which differ by 9. A116216