21000111021011 has 2 divisors, whose sum is σ = 21000111021012. Its totient is φ = 21000111021010.

The previous prime is 21000111021007. The next prime is 21000111021013. The reversal of 21000111021011 is 11012011100012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21000111021011 - 2² = 21000111021007 is a prime.

Together with 21000111021013, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000111020983 and 21000111021001.

It is not a weakly prime, because it can be changed into another prime (21000111021013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500055510505 + 10500055510506.

It is an arithmetic number, because the mean of its divisors is an integer number (10500055510506).

Almost surely, 2^{21000111021011} is an apocalyptic number.

21000111021011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000111021011 is an equidigital number, since it uses as much as digits as its factorization.

21000111021011 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 21000111021011 its reverse (11012011100012), we get a palindrome (32012122121023).

The spelling of 21000111021011 in words is "twenty-one trillion, one hundred eleven million, twenty-one thousand, eleven".