121111111105 has 4 divisors (see below), whose sum is σ = 145333333332. Its totient is φ = 96888888880.

The previous prime is 121111111103. The next prime is 121111111129. The reversal of 121111111105 is 501111111121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 81440032129 + 39671078976 = 285377^2 + 199176^2 .

It is not a de Polignac number, because 121111111105 - 2¹ = 121111111103 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121111111103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12111111106 + ... + 12111111115.

It is an arithmetic number, because the mean of its divisors is an integer number (36333333333).

Almost surely, 2^121111111105 is an apocalyptic number.

It is an amenable number.

121111111105 is a deficient number, since it is larger than the sum of its proper divisors (24222222227).

121111111105 is an equidigital number, since it uses as much as digits as its factorization.

121111111105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24222222226.

The product of its (nonzero) digits is 10, while the sum is 16.

Adding to 121111111105 its sum of digits (16), we get a palindrome (121111111121).

Adding to 121111111105 its reverse (501111111121), we get a palindrome (622222222226).

The spelling of 121111111105 in words is "one hundred twenty-one billion, one hundred eleven million, one hundred eleven thousand, one hundred five".