112121

Properties

Appears in sequences

• Primes that contain digits 1 and 2 only.at n=13A020450
• Primes that are decimal concatenations of n with n + 9.at n=18A032632
• Concatenate (1,n,n,1).at n=12A100846
• Primes of the concatenated form 1nn1 where n is an integer >=0.at n=0A102497
• Smallest prime p with at least two non-overlapping occurrences of n in decimal representation of p.at n=11A103611
• Primes with maximal digit = 2.at n=31A106100
• Primes with digital product = 4.at n=7A107690
• Ternary emirpimes.at n=38A119684
• A monotonic doubly-fractal simple sequence. Erase the last (rightmost) digit of every integer: what is left is the sequence itself. The erased digits, one by one, form also the sequence itself.at n=10A127199
• Prime numbers p of the form 10k+1 for which the pentanacci quintic polynomial x^5-x^4-x^3-x^2-x-1 modulus p is factorizable into five binomials.at n=21A135843
• Primes that become squares when prefixed with a 5.at n=15A167738
• 6-digit numbers k such that: (a) the digits of k are from the set {1, 2, 3, 4, 5}, and (b) any digit that appears in k appears at least twice.at n=18A171725
• Lower Beatty array of sqrt(3).at n=46A182787
• Smallest prime p such that the sum of the squares of the digits of p equals n (or 0 if no such prime exists).at n=11A187553
• List of subwords of A003842 arranged in lexicographic order.at n=21A213975
• Numbers whose largest digit of all divisors is 2.at n=40A221697
• Elements of the Motzkin words sub-operad Motz of TN generated by 00 and 010.at n=22A231872
• Primes having only {1, 2, 4} as digits.at n=38A260267
• Positive numbers n such that (digitsum(n))^2 equals (product of digits(n))^3.at n=10A261778
• Primes whose sum of reciprocal of digits is a prime.at n=32A266815