193 (NUMBER)

'193' is the natural number between 192 and 194. It is also a prime number.

Cardinal	One hundred [and] ninety-three
Ordinal	193rd
Factorization	prime number
Roman numeral	CXCIII
Binary	11000001
Hexadecimal	C1

Contents

In mathematics

References

In mathematics

193 is a prime number, the only odd prime ''p'' known for which 2 is not a primitive root of $4p^2\; +\; 1$.^[1] 193 is a cuban prime, and a twin prime with 191. It is also a lucky prime. 193 is a Proth prime as it is 3 × 2⁶ + 1. It can be written as the difference between the product and the sum of the first four primes.

References

1. E. Friedman, "What's Special About This Number" Accessed 2 January 2006 and again 15 August 2007. "193 is the only known odd prime n for which 2 is not a primitive root of 4''n''² + 1"