Properties of the Number 66640

Sixty-Six Thousand Six Hundred Forty

Basics

Value: 66639 → 66640 → 66641

Parity: even

Prime: No

Previous Prime: 66629

Next Prime: 66643

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 2 ⁴ × 5 × 7 ² × 17

Divisors: 1, 2, 4, 5, 7, 8, 10, 14, 16, 17

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 10000010001010000

Octal: 202120

Duodecimal: 32694

Hexadecimal: 10450

Square: 4440889600

Square Root: 258.14724480420085

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

G.f.: 1/(1 - x*(1-x³)/(1 - x²*(1-x⁴)/(1 - x³*(1-x⁵)/(1 - x⁴*(1-x⁶)/(1 - ...))))), a continued fraction. A227360

T(n,k)=Number of nXk 0..1 arrays with no 1 equal to more than two of its horizontal and vertical neighbors, with the exception of exactly one element. A283203

a(n) = n*(n+1)*(n²+5·n+18)/24. A51744

Number of (w,x,y,z) with all terms in {1,...,n} and w²>x²+y²+z². A212094

Number of partitions of (3, n) into a sum of distinct pairs. A268346

Numbers k such that k·A003557(A003961(k)) divides A353790(k), where A353790(n) = φ(A003973(n)) * A064989(A003973(n)). A353797

Numbers n such that every digit of both n and n² contains a loop (only digits 0,4,6,8,9 in n and n²). A107626

4*(n + 7)³ - 27*(n + 7)² = (4·n +1)*(n+7)². A245033

Number of n X 2 0..1 arrays with no 1 equal to more than two of its horizontal and vertical neighbors, with the exception of exactly one element. A283197

Number of permutations of length n which avoid the patterns 1423, 3421. A116710