Properties of the Number 81919

Eighty-One Thousand Nine Hundred Nineteen

Basics

Value: 81918 → 81919 → 81920

Parity: odd

Prime: Yes

Previous Prime: 81901

Next Prime: 81929

Digit Sum: 28

Digital Root: 1

Palindrome: No

Factorization: 81919

Divisors: 1, 81919

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 10011111111111111

Octal: 237777

Duodecimal: 3B4A7

Hexadecimal: 13fff

Square: 6710722561

Square Root: 286.21495418653444

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

Smallest prime of the form k·2ⁿ - 1, for k >= 2. A127581

a(n) = 5·2ⁿ - 1. A153894

a(0) = 2; for n>=1, a(n) = smallest prime p such that p+1 is divisible by an n-th power > 1. A87522

Primes of the form 4^k + 4^m - 1, where k and m are positive integers. A234310

Primes of the form m = 2ⁱ + 2^j - 1, where i > j >= 0. A239712

a(n) = 5·2^n-1 - 1, n>0, with a(0)=1. A52549

Primes having only {1, 8, 9} as digits. A385783

Primes of the form 2^r*5^s - 1. A77313

a(n) = 5·4ⁿ - 1. A156760

Primes of form 5·2ⁿ-1. A50522