20021011111 has 4 divisors (see below), whose sum is σ = 20021786824. Its totient is φ = 20020235400.

The previous prime is 20021011103. The next prime is 20021011229. The reversal of 20021011111 is 11111012002.

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

It is a cyclic number.

It is not a de Polignac number, because 20021011111 - 2³ = 20021011103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021011711) 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, 347760 + ... + 401221.

It is an arithmetic number, because the mean of its divisors is an integer number (5005446706).

Almost surely, 2^20021011111 is an apocalyptic number.

20021011111 is a deficient number, since it is larger than the sum of its proper divisors (775713).

20021011111 is an equidigital number, since it uses as much as digits as its factorization.

20021011111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775712.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 20021011111 its reverse (11111012002), we get a palindrome (31132023113).

The spelling of 20021011111 in words is "twenty billion, twenty-one million, eleven thousand, one hundred eleven".