Properties of the Number 81280

Eighty-One Thousand Two Hundred Eighty

Basics

Value: 81279 → 81280 → 81281

Parity: even

Prime: No

Previous Prime: 81239

Next Prime: 81281

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 ⁷ × 5 × 127

Divisors: 1, 2, 4, 5, 8, 10, 16, 20, 32, 40

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 10011110110000000

Octal: 236600

Duodecimal: 3B054

Hexadecimal: 13d80

Square: 6606438400

Square Root: 285.0964748992874

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

a(1) = 1, a(n+1) is the numerator of n-th partial fraction of the continued fraction [1; 3, 9, 27, ..., 3ⁿ]. A280219

Number of n X 5 binary arrays with all 1s connected, a path of 1s from upper left corner to lower right corner, and no 1 having more than two 1s adjacent. A163688

Number of n X 8 binary arrays with all 1's connected, a path of 1's from upper left corner to lower right corner, and no 1 having more than two 1's adjacent. A163691

Expansion of e.g.f.: 1/(1-tan(sin(x))). A190123

Numbers which have only digits 0 and 1 in bases 3 and 5. A268337

Array read by antidiagonals: T(m,n) is the number of m X n binary arrays with all 1's connected, a path of 1's from upper left corner to lower right corner, and no 1 having more than two 1's adjacent. A391818

Binomial transform of Chebyshev coefficients A006974. A81280