21212021211 has 32 divisors (see below), whose sum is σ = 30610836480. Its totient is φ = 13021689600.

The previous prime is 21212021161. The next prime is 21212021221. The reversal of 21212021211 is 11212021212.

It is not a de Polignac number, because 21212021211 - 2¹¹ = 21212019163 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21212021221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 616581 + ... + 650073.

It is an arithmetic number, because the mean of its divisors is an integer number (956588640).

Almost surely, 2^21212021211 is an apocalyptic number.

21212021211 is a deficient number, since it is larger than the sum of its proper divisors (9398815269).

21212021211 is a wasteful number, since it uses less digits than its factorization.

21212021211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33827.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21212021211 its reverse (11212021212), we get a palindrome (32424042423).

Subtracting from 21212021211 its reverse (11212021212), we obtain a palindrome (9999999999).

The spelling of 21212021211 in words is "twenty-one billion, two hundred twelve million, twenty-one thousand, two hundred eleven".