21211021211 has 8 divisors (see below), whose sum is σ = 21424204848. Its totient is φ = 20997900000.

The previous prime is 21211021171. The next prime is 21211021213. The reversal of 21211021211 is 11212011212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21211021211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211021213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 989396 + ... + 1010606.

It is an arithmetic number, because the mean of its divisors is an integer number (2678025606).

Almost surely, 2^21211021211 is an apocalyptic number.

21211021211 is a deficient number, since it is larger than the sum of its proper divisors (213183637).

21211021211 is a wasteful number, since it uses less digits than its factorization.

21211021211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31213.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21211021211 its reverse (11212011212), we get a palindrome (32423032423).

Subtracting from 21211021211 its reverse (11212011212), we obtain a palindrome (9999009999).

The spelling of 21211021211 in words is "twenty-one billion, two hundred eleven million, twenty-one thousand, two hundred eleven".