20112111010021 has 4 divisors (see below), whose sum is σ = 20114088806700. Its totient is φ = 20110133213344.

The previous prime is 20112111010001. The next prime is 20112111010031. The reversal of 20112111010021 is 12001011121102.

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 16823368656900 + 3288742353121 = 4101630^2 + 1813489^2 .

It is a cyclic number.

It is not a de Polignac number, because 20112111010021 - 2⁹ = 20112111009509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20112111009983 and 20112111010010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20112111010001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 988883086 + ... + 988903423.

It is an arithmetic number, because the mean of its divisors is an integer number (5028522201675).

Almost surely, 2^{20112111010021} is an apocalyptic number.

It is an amenable number.

20112111010021 is a deficient number, since it is larger than the sum of its proper divisors (1977796679).

20112111010021 is a wasteful number, since it uses less digits than its factorization.

20112111010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1977796678.

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

Adding to 20112111010021 its reverse (12001011121102), we get a palindrome (32113122131123).

The spelling of 20112111010021 in words is "twenty trillion, one hundred twelve billion, one hundred eleven million, ten thousand, twenty-one".