111111012121021 has 16 divisors (see below), whose sum is σ = 121330227211200. Its totient is φ = 100911503952000.

The previous prime is 111111012121009. The next prime is 111111012121051. The reversal of 111111012121021 is 120121210111111.

It is a cyclic number.

It is not a de Polignac number, because 111111012121021 - 2¹⁹ = 111111011596733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111111012120986 and 111111012121004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111111012121051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 642809235 + ... + 642982063.

It is an arithmetic number, because the mean of its divisors is an integer number (7583139200700).

Almost surely, 2^{111111012121021} is an apocalyptic number.

111111012121021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111111012121021 is a deficient number, since it is larger than the sum of its proper divisors (10219215090179).

111111012121021 is a wasteful number, since it uses less digits than its factorization.

111111012121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229500.

The product of its (nonzero) digits is 8, while the sum is 16.

Adding to 111111012121021 its reverse (120121210111111), we get a palindrome (231232222232132).

The spelling of 111111012121021 in words is "one hundred eleven trillion, one hundred eleven billion, twelve million, one hundred twenty-one thousand, twenty-one".