This number is a prime.

+ The smallest Francesca-Carlotta prime, i.e., if a Fibonacci-like sequence is formed with the first term equal to the number of digits in n and the second term equal to the sum of the decimal digits in n, then n itself occurs as a term in the sequence after the first two terms. [Russo]

+ 193 * 1070 + 1 has only 2 prime factors. [Brown]

+ The only odd prime p known for which 2 is not a primitive root of 4p^2 + 1.

+ The smallest prime whose reversal is a Smith number. [Loungrides]

+ The square of 193 (37249) concatenated with its reverse (which is a prime) results in a palindrome that is the product of 2 palindromes, one non-prime (1001) and one prime (3721273). [Trotter]

+ The longest decisive game of chess (as of 1980) was played between Stepak and Masian in Israel, and lasted a whopping 193 moves! [Patterson]

+ The smallest prime whose fifth power contains all digits from 1 to 9 (zeroless pandigital). [Gupta]

+ 193/71 is the closest ratio of two primes less than 2000 to the number e.

+ 193 can be formed from the sum of products of the first three twin primes pairs: 3*5 + 5*7 + 11*13 = 193 is prime. [Post]

+ 193 can be written as the difference between the product and the sum of the first four primes. [Poo Sung]

+ The unique nontrivial Magic Hexagon is one with 19 cells and order (or side) 3. Note that 19 and 3 are two primes that concatenate to form 193. [Beedassy]

+ "There are 193 species of monkeys and apes, 192 of them are covered with hair." Desmond Morris, British zoologist and ethologist

+ A woman in Texas was convicted of murder in March 2004 for stabbing her husband 193 times.

+ The smallest prime which is one more than the product of three distinct composite numbers. [Porter]

+ The largest prime that is the sum of the reversals of two double-digit primes (i.e., 59 and 89). [Loungrides]

+ 193 = 2*3*5*7 - (2+3+5+7), i.e., the product of the first four primes minus the sum of the first four primes. [Alves]

+ The only non-titanic prime of form 97^n-96^n, where n is an integer. [Loungrides]

+ p44# has average digit exactly 4 and is the largest primorial with such a whole number average. [Merickel]

+ If A=1, B=2, C=3, ..., Z=26, then 'PILLAI PRIME NUMBER' is a Pillai prime number. [Homewood]

+ The Knights Templar existed for 193 years. [Homewood]

+ There are 193 prime days in prime months added to the number of composite days in composite months in a leap year. [Homewood]

+ 193 is the smallest prime number that appears in the square of its prime index (44^2 = 1936). The next such prime is 3112771 for which 224346^2 = 50331127716. [Gaydos]

+ 193 is the smallest prime p where p^(digit-sum of p) terminates in the digits of p and the last digit of p is the digit-length of p. [Worrom]

(There are 10 curios for this number that have not yet been approved by an editor.)

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