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Properties of the Number 66809

Sixty-Six Thousand Eight Hundred Nine

Basics

Value: 66808 → 66809 → 66810

Parity: odd

Prime: Yes

Previous Prime: 66797

Next Prime: 66821

Digit Sum: 29

Digital Root: 2

Palindrome: No

Factorization: 66809

Divisors: 1, 66809

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

8509 Try Today's Challenge

Representations

Binary: 10000010011111001

Octal: 202371

Duodecimal: 327B5

Hexadecimal: 104f9

Square: 4463442481

Square Root: 258.4743701027241

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 p such that A001175(p) = (p-1)/7. A308792
Sum of the second largest parts of the partitions of n into 9 parts. A326472
Primes having only {0, 6, 8, 9} as digits. A53580
Triangle read by rows: T(n,k) number of ways of partitioning the (n+4)-element multiset {1,1,1,1,1,2,3,...,n} into exactly k nonempty parts, n >= 0 and 1 <= k <= n + 4. A291119
Balanced primes of order one ending in 9. A303095
Primes that contain all the digits {0,6,8,9} and only these digits. A156200
Number of n X 2 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4. A239844
Number of nX5 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4. A240759
Primes obtained by merging 5 successive digits in the decimal expansion of sqrt(2) + sqrt(3) + sqrt(5). A241221
a(n) = ∑k=1..n k*[ (n/k)*[ (n/k)*[ n/k ] ] ]. A24933