21112111011 has 16 divisors (see below), whose sum is σ = 29814372000. Its totient is φ = 13242797568.

The previous prime is 21112110961. The next prime is 21112111019. The reversal of 21112111011 is 11011121112.

It is not a de Polignac number, because 21112111011 - 2¹⁵ = 21112078243 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21112111019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111765 + ... + 233913.

It is an arithmetic number, because the mean of its divisors is an integer number (1863398250).

Almost surely, 2^21112111011 is an apocalyptic number.

21112111011 is a deficient number, since it is larger than the sum of its proper divisors (8702260989).

21112111011 is a wasteful number, since it uses less digits than its factorization.

21112111011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125558.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 21112111011 its reverse (11011121112), we get a palindrome (32123232123).

The spelling of 21112111011 in words is "twenty-one billion, one hundred twelve million, one hundred eleven thousand, eleven".