21011111111011 has 12 divisors (see below), whose sum is σ = 24441572369592. Its totient is φ = 18009467978208.

The previous prime is 21011111110993. The next prime is 21011111111027. The reversal of 21011111111011 is 11011111111012.

It is not a de Polignac number, because 21011111111011 - 2³¹ = 21008963627363 is a prime.

It is a super-3 number, since 3×21011111111011³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21011111110982 and 21011111111000.

It is not an unprimeable number, because it can be changed into a prime (21011111111071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26598111 + ... + 27376663.

It is an arithmetic number, because the mean of its divisors is an integer number (2036797697466).

Almost surely, 2^{21011111111011} is an apocalyptic number.

21011111111011 is a deficient number, since it is larger than the sum of its proper divisors (3430461258581).

21011111111011 is an equidigital number, since it uses as much as digits as its factorization.

21011111111011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1329330 (or 1329323 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 13.

Adding to 21011111111011 its reverse (11011111111012), we get a palindrome (32022222222023).

Subtracting from 21011111111011 its reverse (11011111111012), we obtain a palindrome (9999999999999).

The spelling of 21011111111011 in words is "twenty-one trillion, eleven billion, one hundred eleven million, one hundred eleven thousand, eleven".