Properties of the Number 191

One Hundred Ninety-One

Basics

Value: 190 → 191 → 192

Parity: odd

Prime: Yes

Previous Prime: 181

Next Prime: 193

Digit Sum: 11

Digital Root: 2

Palindrome: Yes

Factorization: 191

Divisors: 1, 191

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10111111

Octal: 277

Duodecimal: 13B

Hexadecimal: bf

Square: 36481

Square Root: 13.820274961085254

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: Yes

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

The prime numbers. A40

Powers of primes. Alternatively, 1 and the prime powers (p^k, p prime, k >= 1). A961

Lesser of twin primes. A1359

Palindromes in base 10. A2113

Prime numbers at the beginning of the 20th century (today 1 is no longer regarded as a prime). A8578

Numbers k such that (35·10^k - 11)/3 is prime. A268448

Central polygonal numbers (the Lazy Caterer's sequence): n(n+1)/2 + 1; or, maximal number of pieces formed when slicing a pancake with n cuts. A124

Sophie Germain primes p: 2p+1 is also prime. A5384

Primes of the form 4·k + 3. A2145

Prime powers: numbers of the form p^k where p is a prime and k >= 1. A246655

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