21020211011 has 2 divisors, whose sum is σ = 21020211012. Its totient is φ = 21020211010.

The previous prime is 21020210963. The next prime is 21020211029. The reversal of 21020211011 is 11011202012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020211011 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 21020210983 and 21020211001.

It is not a weakly prime, because it can be changed into another prime (21020211041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510105505 + 10510105506.

It is an arithmetic number, because the mean of its divisors is an integer number (10510105506).

Almost surely, 2^21020211011 is an apocalyptic number.

21020211011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020211011 is an equidigital number, since it uses as much as digits as its factorization.

21020211011 is an evil number, because the sum of its binary digits is even.

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

Adding to 21020211011 its reverse (11011202012), we get a palindrome (32031413023).

The spelling of 21020211011 in words is "twenty-one billion, twenty million, two hundred eleven thousand, eleven".