21002100111011 has 16 divisors (see below), whose sum is σ = 21733200689760. Its totient is φ = 20282455591680.

The previous prime is 21002100110993. The next prime is 21002100111023. The reversal of 21002100111011 is 11011100120012.

It is a cyclic number.

It is not a de Polignac number, because 21002100111011 - 2³⁰ = 21001026369187 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002100110983 and 21002100111001.

It is not an unprimeable number, because it can be changed into a prime (21002100111911) 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, 4840685 + ... + 8089278.

It is an arithmetic number, because the mean of its divisors is an integer number (1358325043110).

Almost surely, 2^{21002100111011} is an apocalyptic number.

21002100111011 is a deficient number, since it is larger than the sum of its proper divisors (731100578749).

21002100111011 is a wasteful number, since it uses less digits than its factorization.

21002100111011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12930406.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21002100111011 its reverse (11011100120012), we get a palindrome (32013200231023).

Subtracting from 21002100111011 its reverse (11011100120012), we obtain a palindrome (9990999990999).

The spelling of 21002100111011 in words is "twenty-one trillion, two billion, one hundred million, one hundred eleven thousand, eleven".