199999

Properties

Appears in sequences

• Primes that contain digits 1 and 9 only.at n=23A020457
• Smallest prime containing exactly n 9's.at n=5A037071
• Smallest number whose sum of digits is n.at n=46A051885
• Primes of the form 1999...999.at n=3A055558
• a(n) is the smallest number k such that the letter "N" appears n times when k is written in English.at n=13A060227
• Primes at which sum of digits strictly increases.at n=27A061248
• Smallest prime ending in exactly n 9's.at n=4A065582
• Smallest prime with digit sum n, or 0 if no such prime exists.at n=45A067180
• a(n) = 2*10^(n-1) - 1.at n=5A067272
• The smallest prime with a possible given digit sum.at n=30A067523
• Smaller of two consecutive primes which have no common digits.at n=22A068803
• Number of palindromes of length <= n.at n=9A070199
• Smallest prime whose digital sum is equal to the n-th composite number, or 0 if no such prime exists.at n=30A073867
• Primes of the form 2^r*5^s - 1.at n=22A077313
• a(n) = smallest k such that 2k has digit sum = n.at n=46A077491
• Smallest prime == 1 (mod n-th unary number U(n) = (10^n-1)/9).at n=4A083808
• If k is a number with exactly two distinct decimal digits, say a and b, neither of which is 0 (i.e., a member of A101594), define the self-complement of k, SC(k), to be the number obtained by replacing a with b and vice versa. E.g. SC(232233) = 323322. Sequence contains primes p such that SC(p) is also a prime.at n=35A083983
• Smallest prime whose product of digits is 3^n.at n=10A088653
• Primes of the form identical digits preceded by a 1.at n=7A090149
• Near-repdigit primes with 9 as repeated digit.at n=22A105975