| № | Пользователь | Рейтинг |
|---|---|---|
| 1 | tourist | 4009 |
| 2 | jiangly | 3823 |
| 3 | Benq | 3738 |
| 4 | Radewoosh | 3633 |
| 5 | jqdai0815 | 3620 |
| 6 | orzdevinwang | 3529 |
| 7 | ecnerwala | 3446 |
| 8 | Um_nik | 3396 |
| 9 | ksun48 | 3390 |
| 10 | gamegame | 3386 |
| Страны | Города | Организации | Всё → |
| № | Пользователь | Вклад |
|---|---|---|
| 1 | cry | 167 |
| 2 | Um_nik | 163 |
| 3 | maomao90 | 162 |
| 3 | atcoder_official | 162 |
| 5 | adamant | 159 |
| 6 | -is-this-fft- | 158 |
| 7 | awoo | 157 |
| 8 | TheScrasse | 154 |
| 9 | Dominater069 | 153 |
| 9 | nor | 153 |
Hi!
Today I was surfing Wikipedia and came across this article — Palindromic prime
This article says that the largest known palindromic prime is $$$10^{474500}$$$ + $$$999 * 10^{237249} + 1$$$.
Well it is easy to see that this number is palindrome, but... why is it prime?
I don't find any proof, and I am really curios — how to proof that this number is prime, when number is quite big?
In general, it's quite hard. There is a result from 2002 for which later authors got the Godel prize which proves that primality testing can in fact be done in polynomial time, check this wikipedia link: AKS primality test. There is a lot of advanced research, especially for the uses in cryptography, and the answer to your question is likely not simple (the prime you mention is huge). I am curious if someone has a more optimistic answer...