20011122111 has 4 divisors (see below), whose sum is σ = 26681496152. Its totient is φ = 13340748072.

The previous prime is 20011122029. The next prime is 20011122137. The reversal of 20011122111 is 11122111002.

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

It is not a de Polignac number, because 20011122111 - 2³⁴ = 2831252927 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 (20011122151) 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, 3335187016 + ... + 3335187021.

It is an arithmetic number, because the mean of its divisors is an integer number (6670374038).

Almost surely, 2^20011122111 is an apocalyptic number.

20011122111 is a deficient number, since it is larger than the sum of its proper divisors (6670374041).

20011122111 is an equidigital number, since it uses as much as digits as its factorization.

20011122111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6670374040.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 20011122111 its reverse (11122111002), we get a palindrome (31133233113).

It can be divided in two parts, 200111 and 22111, that added together give a palindrome (222222).

The spelling of 20011122111 in words is "twenty billion, eleven million, one hundred twenty-two thousand, one hundred eleven".