223 (another Prime Pages' Curiosity)
 Curios: Curios Search:   Participate: The largest prime which cannot be represented with less than 37 5th powers. The number of primes and the number of composites that cannot be written as the sum of two primes, up to 223, are equal. [Honaker] The sums of the nth powers of its digits are prime for all n between 1 and 6 inclusive: sum of digits = 7, sum of squares of digits = 17, sum of cubes of digits = 43, sum of fourth powers = 113, sum of fifth powers = 307 and sum of sixth powers = 857. [Trotter] One Saros cycle is almost exactly 223 synodic months. Prime in the decimal expansion of square root of 5. [Haga] A chicken and human have 223 enzymes of identical sequence length. [Jolly] The prime factors of 2p - 1 are all of the form 2kp + 1, where k is a positive integer, and p is an odd prime. Fermat used this fact to show that 223 divides the Mersenne number M(37). A prime extracted from the names of the most famous Star Wars droids, i.e., R2-D2 and C-3PO. May the Force of Prime Numbers be with you! [Capelle] The sum of the digits of first primes up to 223 is 449. Note the prime digits and their squares. [Silva] The smallest prime showing a repeated prime digit. [Silva] The smallest prime whose reversal has more than two prime divisors. [Silva] The largest gear in the Antikythera mechanism most likely had 223 teeth in connection with the prediction of lunar eclipses. [Beedassy] The smallest prime formed from three prime digits. [Silva] 223 = -01+23+45+67+89. [Silva] "The children of Hashum, two hundred twenty and three." (Ezra 2:19, KJV) [Dorton] (There are 9 curios for this number that have not yet been approved by an editor.) Prime Curios! © 2000-2018 (all rights reserved)  privacy statement