Properties of the Number 66720

Sixty-Six Thousand Seven Hundred Twenty

Basics

Value: 66719 → 66720 → 66721

Parity: even

Prime: No

Previous Prime: 66713

Next Prime: 66721

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 2 ⁵ × 3 × 5 × 139

Divisors: 1, 2, 3, 4, 5, 6, 8, 10, 12, 15

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10000010010100000

Octal: 202240

Duodecimal: 32740

Hexadecimal: 104a0

Square: 4451558400

Square Root: 258.30214865540705

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

Amicable triples: numbers such that σ(x) = σ(y) = σ(z) = x+y+z, x<y<z. We order these triples according to the common value of σ. Sequence gives·numbers. A125490

Numbers k such that σ(φ(k)) = k-φ(k). A70171

Sum of the three largest parts in the partitions of 4n into 4 parts. A243011

Numbers k such that (349·10^k - 7)/9 is prime. A284595

The greedy rational packing sequence: a(1) = 1; for n > 1, a(n) is smallest number such that the ratios a(i)/a(j) for 1 <= i < j <= n are all distinct. A66720

Number of (4+1)X(n+1) 0..1 arrays with every 2X2 subblock sum nondecreasing horizontally, vertically and antidiagonally ne-to-sw. A253329