21321110211 has 4 divisors (see below), whose sum is σ = 28428146952. Its totient is φ = 14214073472.

The previous prime is 21321110207. The next prime is 21321110233. The reversal of 21321110211 is 11201112312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21321110211 - 2² = 21321110207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21321110011) 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 in 3 ways as a sum of consecutive naturals, for example, 3553518366 + ... + 3553518371.

It is an arithmetic number, because the mean of its divisors is an integer number (7107036738).

Almost surely, 2^21321110211 is an apocalyptic number.

21321110211 is a deficient number, since it is larger than the sum of its proper divisors (7107036741).

21321110211 is an equidigital number, since it uses as much as digits as its factorization.

21321110211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7107036740.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21321110211 its reverse (11201112312), we get a palindrome (32522222523).

The spelling of 21321110211 in words is "twenty-one billion, three hundred twenty-one million, one hundred ten thousand, two hundred eleven".