20111120021 has 4 divisors (see below), whose sum is σ = 20114054700. Its totient is φ = 20108185344.

The previous prime is 20111119993. The next prime is 20111120027. The reversal of 20111120021 is 12002111102.

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 3370383025 + 16740736996 = 58055^2 + 129386^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111120021 - 2³⁰ = 19037378197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20111119984 and 20111120011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111120027) 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, 1457036 + ... + 1470773.

It is an arithmetic number, because the mean of its divisors is an integer number (5028513675).

Almost surely, 2^20111120021 is an apocalyptic number.

It is an amenable number.

20111120021 is a deficient number, since it is larger than the sum of its proper divisors (2934679).

20111120021 is an equidigital number, since it uses as much as digits as its factorization.

20111120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2934678.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 20111120021 its reverse (12002111102), we get a palindrome (32113231123).

The spelling of 20111120021 in words is "twenty billion, one hundred eleven million, one hundred twenty thousand, twenty-one".