Properties of the Number 27381

Twenty-Seven Thousand Three Hundred Eighty-One

Basics

Value: 27380 → 27381 → 27382

Parity: odd

Prime: No

Previous Prime: 27367

Next Prime: 27397

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 3 × 9127

Divisors: 1, 3, 9127, 27381

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 110101011110101

Octal: 65365

Duodecimal: 13A19

Hexadecimal: 6af5

Square: 749719161

Square Root: 165.47205202087753

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

Numbers k such that lcm(1,2,3,...,k)/13 equals the denominator of the k-th harmonic number H(k). A112818

Square array A(1,k) = A265907(k), A(n>1,k) = A(n-1, k+1) - A(n-1, k); successive differences of A265907 read by descending antidiagonals as A(1,1), A(1,2), A(2,1), A(1,3), A(2,2), A(3,1), ... A275960

Number of partitions of n such that the absolute value of the difference between the number of odd parts and the number of even parts is <=1. A239835

a(1) = 1; for n > 1, a(n) = a(n-1) + A255411(a(n-1)). A265907

a(n) = 20·n² + 1. A158493

Shorthand for A157035, the largest prime with 2ⁿ digits. A157036

Transpose of array A275960. A275961

Semiprimes of the form 5·n² + 1. A212707

Concatenations C1 and C2 and C3 are all prime (see the comment lines). A34818

Numbers n such that 7ⁿ-6^n-1 is prime. A273524