21012102011 has 2 divisors, whose sum is σ = 21012102012. Its totient is φ = 21012102010.

The previous prime is 21012101993. The next prime is 21012102037. The reversal of 21012102011 is 11020121012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21012102011 - 2³⁰ = 19938360187 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012101983 and 21012102001.

It is not a weakly prime, because it can be changed into another prime (21012102061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506051005 + 10506051006.

It is an arithmetic number, because the mean of its divisors is an integer number (10506051006).

Almost surely, 2^21012102011 is an apocalyptic number.

21012102011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012102011 is an equidigital number, since it uses as much as digits as its factorization.

21012102011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21012102011 its reverse (11020121012), we get a palindrome (32032223023).

The spelling of 21012102011 in words is "twenty-one billion, twelve million, one hundred two thousand, eleven".