How to find 26 th prime number?
411704
Do you mean the 26th Mersenne Prime? It has already been found, In 1978.\n\nIt is (2^23209) - 1, a number with 6,987 digits in it.\n\nThey are up to 43 Mersenne Primes now. All Mersenne Primes are of the form (2^n) -1, where n is prime, but only a minority of prime values of n generate a Mersenne number.\n\nIt takes many days of looking by supercomputers to find these very large numbers, the largest of which has over 9 million digits. That took 50 days to find and 5 days to check that it had no factors. \n\nThere is no formula, just systematic trial and error and dividing by all primes up to the square root of the candidate prime to see if they divide into it (modulo 0) exactly or not.\n\nThe 26th ordinary prime, counting from 2 upwards as the 1st prime number, is relatively small in comparison.\n\n2, 3, 5, 7, 11\n13, 17, 19, 23, 29\n31, 37, 41, 43, 47\n53, 59, 61, 67, 71,\n73, 79, 83, 89, 97 \n\nmaking the 26th prime 101
90213
it isn't prime: it's divisible by 7 (which is one of my favourite numbers).\nIf you add it to 668^2 you get 669^2 (but that's a trick you can do with every odd number).
657112
Dear Visit and search in the left side(Curios search):\nhttp://primes.utm.edu/curios/page.php
1121426
I don't know if this is what you are looking for but simplified this fraction would be 24/43 (divided by 3). And you cannot simplify it any further because 43 is a prime number, as far as I remember...
175248
Unfortunately I don't know of a quick method but I can help you a little here. \n\nFirst, as you probably already know, prime numbers can only be evenly divided by 1 and the number itself.\n\nSecond, since all numbers are a product of prime numbers you can save time in by not testing division by non-prime numbers like 4 and 6 and 9 and so on.\n\nThird, you only have to test those prime number that are smaller than the square root of the number.\n\nIn your example, 117, you need only test the prime numbers less than 10.81.... since that is the square root of 117. So do a trial divide of 117 by 2, 3, 5, and 7.\n\nOf course there are a few other rules that can help you eliminate the first three choices. If the number is odd, it can't be evenly divided by 2. If the sum of digits isn't divisible by 3 then the number isn't either. And all numbers that are divisible by 5 end in 5 or zero.\n\nFor 117, the number is odd so that eliminates 2. The sum of 1 and 1 and 7 is 9 which is divisible by 3 so 117 is divisible by three and therefore not prime.\n\nSo now you may notice that 117 is divisible by 3 and 39 but I said you only need to test numbers smaller than the square root. What about 39? Well, since the number is divisible by three that alone proves the number is not prime. If you want the full prime factorization, you need to keep dividing.\n\nGood luck.
792528
Do a prime factorization of each number:\n\n18 = 2 x 3 x 3\n30 = 2 x 3 x 5\n42 = 2 x 3 x 7\n\nThe prime factors they have in common are a two (2) and a three (3).\n\n2 x 3 = 6\n\nGCF(18, 30, 42) = 6
181922
{determinses whether a number is prime}\nvar number, j : integer;\n    prime : boolean;\nbegin\n     writeln('type your number');\n     readln( number );\n     prime := true;\n     for j := 2 to abs(number) -1 do{allows neg nos.}\n         if number mod j = 0 then\n            prime := false;\n     if prime then\n        writeln( number , ' is a prime number')\n     else\n         writeln( number , ' is not a prime number');\n     readln\nend.
630729
2.Only even number to be prime
293052
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97\n\n101 is the next prime number ... \nso 24 prime numbers between 1 - 100
936530
Try to factorise number 319.\nIt is 11 * 29\nSo you have 11 rows 29 people per row \nor 29 rows with 11 people per row.\n\nIf you wonder how to find it it is simple\nTry to divide 319 with prime numbers\n\n2,3,5,7,11,13,17\n\nOnly 11 is ok!
136689
2*3*5*7*11*13 = 30030\n\nYou're correct.\n\n(I see questions regarding "1" as a prime - Google "prime numbers" and you'll find many links starting at 2. Just sayin'.....)
1067663
Seven prime integers.\n\n7\n17\n37\n47\n67\n71\n73
522039
Primes from 50 to 100\n53\n59\n61\n67\n71\n73\n79\n83\n89\n97
357003
if you take the number N and add one it must be prime... \n\ntake any number it can be writen as a product of primes, so in this case let us just examin N+1/p_j\n\nclearly N/p_j is an integer, and 1/p_j is clearly not an integer. \n\nSo if N were not prime then there would exist p_j such that N+1/p_j was an integer.   But that can not be true, therefore the assumption that there are only finitly many primes is incorrect, and the opposite is true, there are infinitly many primes QED
436162
no it is not\nhere is a list\n\n2, 3, 5, 7, 11, 13, 17, 19, 23, 29,\n31, 37, 41, 43, 47, 53, 59, 61, 67, 71\n73, 79, 83, 89, 97, 101, 103, 107, 109, 113,\n127, 131, 137, 139, 149, 151, 157, 163, 167, 173,\n179, 181, 191, 193, 197, 199, 211, 223, 227, 229,\n233, 239, 241, 251, 257, 263, 269, 271, 277, 281,\n283, 293. \n\n\n\nhow did I find out?  google?  prime numbers between 100 and 200
84784
You should really just draw out the factor tree.\n\nYou will get 2power4 times 3 in prime factorization.\n\nYou just find the lowest prime number and a multiple and branch down the tree in the same process. Also bring down the primes. Once you have all prime numbers you put them together them to get the prime factorization.\n\nHere is the tree:\n\n                             48\n                            /  &#92;\n                           2 * 24\n                          /   /  &#92;\n                         2 * 2 * 12\n                        /   /   /  &#92;\n                       2 * 2 * 2 *  6\n                      /   /   /    / &#92;\n                     2 * 2 * 2  * 2 * 3\n\n                             2^4 * 3
652436
Dear Visit and search in the left side(Curios search):\nhttp://primes.utm.edu/curios/page.php...