 8999 (another Prime Pages' Curiosity) Curios: Curios Search:   Participate:  GIMPS has discovered a new largest known prime number: 282589933-1 (24,862,048 digits) A prime number whose sum of digits (sod) is greater than or equal to the near-repdigit prime 8999 must be titanic. ```The smallest prime numbers whose sum of digits equals the n-th prime: 1 -> sod(2)=2 [Honaker] 2 -> sod(3)=3 [Honaker] 3 -> sod(5)=5 [Honaker] 4 -> sod(7)=7 [Honaker] 5 -> sod(29)=11 [Honaker] 6 -> sod(67)=13 [Honaker] 7 -> sod(89)=17 [Honaker] 8 -> sod(199)=19 [Honaker] 9 -> sod(599)=23 [Honaker] 10 -> sod(2999)=29 [Honaker] 11 -> sod(4999)=31 [Honaker] 12 -> sod(29989)=37 [Chua] 13 -> sod(59999)=41 [Chua] 14 -> sod(79999)=43 [Chua] 15 -> sod(389999)=47 [Chua] 16 -> sod(989999)=53 [Chua] 17 -> sod(6999899)=59 [Chua] 18 -> sod(8989999)=61 [Chua] 19 -> sod(59899999)=67 [Chua] 20 -> sod(89999999)=71 [Chua] 21 -> sod(289999999)=73 [Chua] 22 -> sod(799999999)=79 [Chua] 23 -> sod(3999998999)=83 [Chua] 24 -> sod(18989999999)=89 [Gaydos] 25 -> sod(79999999999)=97 [Marcus] 26 -> sod(399999998999)=101 [Marcus] 27 -> sod(599999899999)=103 [Marcus] 28 -> sod(999998999999)=107 [Wilson] 29 -> sod(2999998999999)=109 [Luhn] 30 -> sod(6999998999999)=113 [Gaydos] 31 -> sod(299999989999999)=127 [Gaydos] 32 -> sod(789989999999999)=131 [Gaydos] 33 -> sod(3999999999999989)=137 [Gaydos] 34 -> sod(5999999999899999)=139 [Gaydos] 35 -> sod(69989999999999999)=149 [Gaydos] 36 -> sod(89989999999999999)=151 [Gaydos] 37 -> sod(599999999999899999)=157 [Rivera] 38 -> sod(2999998999999999999)=163 [Rivera] 39 -> sod(7799999999999999999)=167 [Gaydos] 40 -> sod(29999999999999999999)=173 [Bajpai] 41 -> sod(89999999999999999999)=179 [Bajpai] 42 -> sod(299999899999999999999)=181 [Gupta] 43 -> sod(4799999999999999999999)=191 [Gupta] 44 -> sod(5899999999999999999999)=193 [Gupta] 45 -> sod(9998999999999999999999)=197 [Bajpai] 46 -> sod(29998999999999999999999)=199 [Gaydos] 47 -> sod(599999999999899999999999)=211 [Gupta] 48 -> sod(17989999999999999999999999)=223 [Gaydos] 49 -> sod(39998999999999999999999999)=227 [Gupta] 50 -> sod(59999999999899999999999999)=229 [Gupta] 51 -> sod(99999999999999998999999999)=233 [Rivera] 52 -> sod(698999999999999999999999999)=239 [Gupta] 53 -> sod(899999998999999999999999999)=241 [Gupta] 54 -> sod(18899999999999999999999999999)=251 [Gupta] 55 -> sod(59999999999999999999999999999)=257 [Gupta] 56 -> sod(489999999899999999999999999999)=263 [Gaydos] 57 -> sod(899999999999999999999999999999)=269 [Gupta] 58 -> sod(2999999999999999999999989999999)=271 [Gupta] 59 -> sod(8999899999999999999999999999999)=277 [Gupta] . . . 1117 -> sod(see number)=8999. [Bajpai] ``` (8999, 9001) is the only case of twin primes less than a googol of form (9*10^n-1, 9*10^n+1). [Loungrides] Warning: Do not subtract the prime number 8999 from its reversal and turn the difference upside down. [Heath] The largest four-digit near-repdigit prime is the reversal of the largest four-digit semiprime. [Silva] 8999 followed by seventy-two 3's is a prime whose sum of digits equals the prime 251. [Bajpai]   To link to this page use /curios/page.php?number_id=8689 Prime Curios! © 2000-2020 (all rights reserved)  privacy statement   (This page was generated in 0.0332 seconds.)