Properties of the Number 81191

Eighty-One Thousand One Hundred Ninety-One

Basics

Value: 81190 → 81191 → 81192

Parity: odd

Prime: No

Previous Prime: 81181

Next Prime: 81197

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 11 ³ × 61

Divisors: 1, 11, 61, 121, 671, 1331, 7381, 81191

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011110100100111

Octal: 236447

Duodecimal: 3AB9B

Hexadecimal: 13d27

Square: 6591978481

Square Root: 284.9403446337496

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(n) = n³*(n² + 1)/2. A168178

Denominator of H(n)/H(n-1), where H(n) is the n-th harmonic number = ∑_k=1..n 1/k. A193758

Gaps of 10 in sequence A038593 (upper terms). A38660

Numbers n such that the sum of the prime factors of n equals the product of the digits of n. A67173

Composite numbers whose prime factors contain no digits other than 1 and 6. A36306

Numerators of constants A(a) related to the asymptotic LCM of arithmetic progressions a·n+b (a and b coprime). A249225

The terms of A073211 (sums of two powers of 11) divided by 2. A73219

Numerator of the product of the n-th triangular number and the n-th harmonic number. A119786

Where records occur in A127356. A129315

a(n) = A003418(n+1)*H(n), where H(n) = 1 + 1/2 + ... + 1/n is the n-th harmonic number. A379561