21011112011 has 2 divisors, whose sum is σ = 21011112012. Its totient is φ = 21011112010.

The previous prime is 21011111983. The next prime is 21011112047. The reversal of 21011112011 is 11021111012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21011112011 - 2²² = 21006917707 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21011111983 and 21011112001.

It is not a weakly prime, because it can be changed into another prime (21011112061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505556005 + 10505556006.

It is an arithmetic number, because the mean of its divisors is an integer number (10505556006).

Almost surely, 2^21011112011 is an apocalyptic number.

21011112011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011112011 is an equidigital number, since it uses as much as digits as its factorization.

21011112011 is an evil number, because the sum of its binary digits is even.

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

Adding to 21011112011 its reverse (11021111012), we get a palindrome (32032223023).

Subtracting from 21011112011 its reverse (11021111012), we obtain a palindrome (9990000999).

The spelling of 21011112011 in words is "twenty-one billion, eleven million, one hundred twelve thousand, eleven".