121111100111 has 16 divisors (see below), whose sum is σ = 129200617728. Its totient is φ = 113333606400.

The previous prime is 121111100017. The next prime is 121111100119. The reversal of 121111100111 is 111001111121.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 121111100111 - 2²⁶ = 121043991247 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121111100092 and 121111100101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121111100119) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 278006 + ... + 565251.

It is an arithmetic number, because the mean of its divisors is an integer number (8075038608).

Almost surely, 2^121111100111 is an apocalyptic number.

121111100111 is a deficient number, since it is larger than the sum of its proper divisors (8089517617).

121111100111 is a wasteful number, since it uses less digits than its factorization.

121111100111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843442.

The product of its (nonzero) digits is 2, while the sum is 11.

Adding to 121111100111 its reverse (111001111121), we get a palindrome (232112211232).

The spelling of 121111100111 in words is "one hundred twenty-one billion, one hundred eleven million, one hundred thousand, one hundred eleven".