21111011113 has 4 divisors (see below), whose sum is σ = 21163657428. Its totient is φ = 21058364800.

The previous prime is 21111011107. The next prime is 21111011147. The reversal of 21111011113 is 31111011112.

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 17741440809 + 3369570304 = 133197^2 + 58048^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111011113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111011093 and 21111011102.

It is not an unprimeable number, because it can be changed into a prime (21111011413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26322556 + ... + 26323357.

It is an arithmetic number, because the mean of its divisors is an integer number (5290914357).

Almost surely, 2^21111011113 is an apocalyptic number.

It is an amenable number.

21111011113 is a deficient number, since it is larger than the sum of its proper divisors (52646315).

21111011113 is an equidigital number, since it uses as much as digits as its factorization.

21111011113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52646314.

The product of its (nonzero) digits is 6, while the sum is 13.

Adding to 21111011113 its reverse (31111011112), we get a palindrome (52222022225).

Subtracting 21111011113 from its reverse (31111011112), we obtain a palindrome (9999999999).

The spelling of 21111011113 in words is "twenty-one billion, one hundred eleven million, eleven thousand, one hundred thirteen".