1111111112021 has 4 divisors (see below), whose sum is σ = 1112555990700. Its totient is φ = 1109666233344.

The previous prime is 1111111111939. The next prime is 1111111112063. The reversal of 1111111112021 is 1202111111111.

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 637610235025 + 473500876996 = 798505^2 + 688114^2 .

It is a cyclic number.

It is not a de Polignac number, because 1111111112021 - 2²² = 1111106917717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1111111111987 and 1111111112005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1111111112081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 722438186 + ... + 722439723.

It is an arithmetic number, because the mean of its divisors is an integer number (278138997675).

Almost surely, 2^{1111111112021} is an apocalyptic number.

It is an amenable number.

1111111112021 is a deficient number, since it is larger than the sum of its proper divisors (1444878679).

1111111112021 is an equidigital number, since it uses as much as digits as its factorization.

1111111112021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1444878678.

The product of its (nonzero) digits is 4, while the sum is 14.

Adding to 1111111112021 its reverse (1202111111111), we get a palindrome (2313222223132).

It can be divided in two parts, 11111111 and 12021, that multiplied together give a palindrome (133566665331).

The spelling of 1111111112021 in words is "one trillion, one hundred eleven billion, one hundred eleven million, one hundred twelve thousand, twenty-one".