21213311211 has 12 divisors (see below), whose sum is σ = 31776318392. Its totient is φ = 14142207312.

The previous prime is 21213311167. The next prime is 21213311221. The reversal of 21213311211 is 11211331212.

21213311211 is a `hidden beast` number, since 2 + 121 + 331 + 1 + 211 = 666.

It is not a de Polignac number, because 21213311211 - 2¹⁰ = 21213310187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21213311221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43648546 + ... + 43649031.

Almost surely, 2^21213311211 is an apocalyptic number.

21213311211 is a deficient number, since it is larger than the sum of its proper divisors (10563007181).

21213311211 is an frugal number, since it uses more digits than its factorization.

21213311211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87297592 (or 87297580 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 21213311211 its reverse (11211331212), we get a palindrome (32424642423).

The spelling of 21213311211 in words is "twenty-one billion, two hundred thirteen million, three hundred eleven thousand, two hundred eleven".