21312221211 has 12 divisors (see below), whose sum is σ = 30939017200. Its totient is φ = 14136748560.

The previous prime is 21312221201. The next prime is 21312221213. The reversal of 21312221211 is 11212221312.

It is not a de Polignac number, because 21312221211 - 2⁷ = 21312221083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21312221213) 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, 5948020 + ... + 5951601.

Almost surely, 2^21312221211 is an apocalyptic number.

21312221211 is a deficient number, since it is larger than the sum of its proper divisors (9626795989).

21312221211 is a wasteful number, since it uses less digits than its factorization.

21312221211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11899826 (or 11899823 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

Adding to 21312221211 its reverse (11212221312), we get a palindrome (32524442523).

The spelling of 21312221211 in words is "twenty-one billion, three hundred twelve million, two hundred twenty-one thousand, two hundred eleven".