111111111021 has 16 divisors (see below), whose sum is σ = 150955384320. Its totient is φ = 72670678080.

The previous prime is 111111111017. The next prime is 111111111049. The reversal of 111111111021 is 120111111111.

It is not a de Polignac number, because 111111111021 - 2² = 111111111017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111111110988 and 111111111006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111111111091) 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, 3052036 + ... + 3088226.

It is an arithmetic number, because the mean of its divisors is an integer number (9434711520).

Almost surely, 2^111111111021 is an apocalyptic number.

It is an amenable number.

111111111021 is a deficient number, since it is larger than the sum of its proper divisors (39844273299).

111111111021 is a wasteful number, since it uses less digits than its factorization.

111111111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55556.

The product of its (nonzero) digits is 2, while the sum is 12.

Adding to 111111111021 its reverse (120111111111), we get a palindrome (231222222132).

The spelling of 111111111021 in words is "one hundred eleven billion, one hundred eleven million, one hundred eleven thousand, twenty-one".