121211211112111 has 4 divisors (see below), whose sum is σ = 121211239307224. Its totient is φ = 121211182917000.

The previous prime is 121211211112109. The next prime is 121211211112141. The reversal of 121211211112111 is 111211112112121.

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

It is a cyclic number.

It is not a de Polignac number, because 121211211112111 - 2¹ = 121211211112109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121211211112141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6158880 + ... + 16743781.

It is an arithmetic number, because the mean of its divisors is an integer number (30302809826806).

Almost surely, 2^{121211211112111} is an apocalyptic number.

121211211112111 is a deficient number, since it is larger than the sum of its proper divisors (28195113).

121211211112111 is an equidigital number, since it uses as much as digits as its factorization.

121211211112111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28195112.

The product of its digits is 16, while the sum is 19.

Adding to 121211211112111 its reverse (111211112112121), we get a palindrome (232422323224232).

The spelling of 121211211112111 in words is "one hundred twenty-one trillion, two hundred eleven billion, two hundred eleven million, one hundred twelve thousand, one hundred eleven".