21221101211 has 2 divisors, whose sum is σ = 21221101212. Its totient is φ = 21221101210.

The previous prime is 21221101201. The next prime is 21221101267. The reversal of 21221101211 is 11210112212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21221101211 - 2¹⁴ = 21221084827 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221101201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610550605 + 10610550606.

It is an arithmetic number, because the mean of its divisors is an integer number (10610550606).

Almost surely, 2^21221101211 is an apocalyptic number.

21221101211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221101211 is an equidigital number, since it uses as much as digits as its factorization.

21221101211 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 14.

Adding to 21221101211 its reverse (11210112212), we get a palindrome (32431213423).

The spelling of 21221101211 in words is "twenty-one billion, two hundred twenty-one million, one hundred one thousand, two hundred eleven".