111121120021 has 4 divisors (see below), whose sum is σ = 111866899500. Its totient is φ = 110375340544.

The previous prime is 111121120001. The next prime is 111121120051. The reversal of 111121120021 is 120021121111.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 43508119396 + 67613000625 = 208586^2 + 260025^2 .

It is a cyclic number.

It is not a de Polignac number, because 111121120021 - 2⁹ = 111121119509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111121119983 and 111121120010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111121120001) 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 3 ways as a sum of consecutive naturals, for example, 372889516 + ... + 372889813.

It is an arithmetic number, because the mean of its divisors is an integer number (27966724875).

Almost surely, 2^111121120021 is an apocalyptic number.

It is an amenable number.

111121120021 is a deficient number, since it is larger than the sum of its proper divisors (745779479).

111121120021 is an equidigital number, since it uses as much as digits as its factorization.

111121120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 745779478.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 111121120021 its reverse (120021121111), we get a palindrome (231142241132).

The spelling of 111121120021 in words is "one hundred eleven billion, one hundred twenty-one million, one hundred twenty thousand, twenty-one".