121011211111 has 4 divisors (see below), whose sum is σ = 138298526992. Its totient is φ = 103723895232.

The previous prime is 121011211091. The next prime is 121011211301. The reversal of 121011211111 is 111112110121.

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 121011211111 - 2⁹ = 121011210599 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121011211091 and 121011211100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121011217111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8643657930 + ... + 8643657943.

It is an arithmetic number, because the mean of its divisors is an integer number (34574631748).

Almost surely, 2^121011211111 is an apocalyptic number.

121011211111 is a deficient number, since it is larger than the sum of its proper divisors (17287315881).

121011211111 is an equidigital number, since it uses as much as digits as its factorization.

121011211111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17287315880.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 121011211111 its reverse (111112110121), we get a palindrome (232123321232).

The spelling of 121011211111 in words is "one hundred twenty-one billion, eleven million, two hundred eleven thousand, one hundred eleven".