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weakly primes
A prime is said to be weakly if it cannot be changed into another prime by changing a single digit.

For example, 13 is not a weakly prime since changing its last digit into 7 we obtain another prime, 17. The smallest weakly prime is 294001, indeed changing any of its digits results in a composite number.

A composite number which cannot be turned into a prime by changing a single digit is called unprimeable.

Terence Tao has proved that there are infinite weakly primes.

The first weakly primes are 294001, 505447, 584141, 604171, 971767, 1062599, 1282529, 1524181, 2017963, 2474431, 2690201 more terms

A few extremely weakly primes are known, i.e., prime that become composite if any digit is removed, changed, or inserted. They are 40144044691, 58058453543, 89797181359, 185113489357, 213022025663, and 222498988079.

Weakly primes can also be... (you may click on names or numbers and on + to get more values)

a-pointer 33051769 48441331 74543663 81434501 134143837 136562467 162417733 + 9915415343 9960215141 aban 186000169 696000421 762000461 959000711 2829000323 3124000897 3895000519 + 99059000801 99884000693 alternating 81434501 85478369 123892907 167056709 323032921 349458983 507856387 + 969094909 983810701 amenable 294001 584141 1282529 1524181 2690201 3085553 3326489 + 997686013 998740213 arithmetic 294001 505447 584141 604171 971767 1062599 1282529 + 9608189 9931447 balanced p. 3326489 21089489 21668839 27245539 38178211 42120581 43432409 + 9956909143 9994090871 c.decagonal 3383250781 88540120561 94269493951 c.heptagonal 9545528833 c.square 18539484241 c.triangular 5830255021 32411956519 Chen 584141 971767 1062599 4393139 5575259 6712591 7469797 + 99041179 99778351 congruent 505447 584141 971767 1062599 1524181 2474431 5564453 + 9608189 9931447 Curzon 3326489 7469789 14075273 23462969 31240481 52127189 64085921 + 157553993 162123869 cyclic 294001 505447 584141 604171 971767 1062599 1282529 + 9608189 9931447 d-powerful 3326489 de Polignac 584141 604171 4393139 9016079 9537371 9931447 10506191 + 98701003 98750609 deficient 294001 505447 584141 604171 971767 1062599 1282529 + 9608189 9931447 dig.balanced 8353427 9537371 14075273 34302127 35954509 43414669 46031123 + 195315619 196363373 economical 294001 505447 584141 604171 971767 1062599 1282529 + 18953677 19851991 emirp 1282529 3326489 10564877 14151757 33051769 34349969 35954509 + 198303601 198873523 equidigital 294001 505447 584141 604171 971767 1062599 1282529 + 18953677 19851991 evil 294001 604171 1062599 1282529 3085553 5152507 5564453 + 997367737 998839951 good prime 5564453 59160317 61589579 126517543 happy 604171 3326489 5152507 7469789 7858771 8090057 8353427 8532761 hex 4103337817 Hogben 23402421463 Honaker 6173731 20212327 22138349 34302127 40432489 42145837 43432409 + 944375701 945808223 inconsummate 584141 junction 2474431 7982543 8353427 11593019 17412427 21668839 25151927 + 92519951 99778351 lucky 604171 2474431 6463267 odious 505447 584141 971767 1524181 2017963 2474431 2690201 + 997898039 998740213 Ormiston 2474431 29348797 35009671 67296517 77250497 82764371 83407327 + 1985538197 1993416713 palindromic 79856965897 91507670519 palprime 79856965897 91507670519 pancake 26783972629 56408862787 pernicious 505447 584141 1524181 2017963 2474431 5575259 6173731 + 8639089 9016079 persistent 12695840537 13508267249 21635702849 29473078651 30624891751 31067254859 35986840271 + 90684725371 95440286317 prime 294001 505447 584141 604171 971767 1062599 1282529 + 99999423397 99999446179 Proth 43447484417 62688854017 repunit 23402421463 self 6173731 7469797 10564877 17424721 25081361 25556941 27425521 + 998740213 998839951 strong prime 505447 584141 604171 1062599 5152507 5564453 5575259 + 99157987 99595919 super-d 971767 1062599 1524181 2474431 3326489 6173731 9537371 twin 294001 1062599 1524181 5575259 9608189 12325739 16497121 + 994125569 998839951 uban 13075000087 72047000057 95053000019 96053000053 weak prime 294001 971767 1282529 1524181 2017963 2474431 2690201 + 98643439 98750609 zygodrome 77755114477