21021210211 has 2 divisors, whose sum is σ = 21021210212. Its totient is φ = 21021210210.

The previous prime is 21021210187. The next prime is 21021210227. The reversal of 21021210211 is 11201212012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021210211 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21021210191 and 21021210200.

It is not a weakly prime, because it can be changed into another prime (21021210911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510605105 + 10510605106.

It is an arithmetic number, because the mean of its divisors is an integer number (10510605106).

Almost surely, 2^21021210211 is an apocalyptic number.

21021210211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021210211 is an equidigital number, since it uses as much as digits as its factorization.

21021210211 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21021210211 its reverse (11201212012), we get a palindrome (32222422223).

The spelling of 21021210211 in words is "twenty-one billion, twenty-one million, two hundred ten thousand, two hundred eleven".