199999991

Properties

Appears in sequences

• Primes in which a string of 9's is sandwiched between two 1's.at n=3A068649
• Primes which are a sandwich of numbers using at most one digit between two 1's.at n=14A068685
• Smaller of two consecutive primes which have no common digits.at n=33A068803
• Smallest palindromic prime containing exactly n 9's.at n=6A083980
• Palindromic primes in which all internal digits are 9.at n=4A108848
• Least n-digit prime which differs from the next prime at every corresponding digit.at n=8A114016
• a(n) = n 9's sandwiched between two 1's.at n=7A185123
• Primes of the form XYYYYYYYX, where Y is a single digit.at n=1A228377
• Palindromic primes with strictly increasing sum of digits.at n=30A230045
• Record gaps between palindromic primes (lower end): primes A002385(k) where A002385(k+1) - A002385(k) exceeds A002385(j+1) - A002385(j) for all j < k.at n=13A327428
• Prime numbersat n=11078937