20911111011 has 16 divisors (see below), whose sum is σ = 35405056000. Its totient is φ = 11949206184.

The previous prime is 20911111007. The next prime is 20911111063. The reversal of 20911111011 is 11011111902.

It is not a de Polignac number, because 20911111011 - 2² = 20911111007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20921111011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55320211 + ... + 55320588.

It is an arithmetic number, because the mean of its divisors is an integer number (2212816000).

Almost surely, 2^20911111011 is an apocalyptic number.

20911111011 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20911111011 is a deficient number, since it is larger than the sum of its proper divisors (14493944989).

20911111011 is a wasteful number, since it uses less digits than its factorization.

20911111011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110640815 (or 110640809 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 18.

Adding to 20911111011 its reverse (11011111902), we get a palindrome (31922222913).

The spelling of 20911111011 in words is "twenty billion, nine hundred eleven million, one hundred eleven thousand, eleven".