21213211121321 has 16 divisors (see below), whose sum is σ = 23996091159360. Its totient is φ = 18632258979840.

The previous prime is 21213211121273. The next prime is 21213211121327. The reversal of 21213211121321 is 12312111231212.

It is a cyclic number.

It is not a de Polignac number, because 21213211121321 - 2²⁶ = 21213144012457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21213211121327) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 490094600 + ... + 490137881.

It is an arithmetic number, because the mean of its divisors is an integer number (1499755697460).

Almost surely, 2^{21213211121321} is an apocalyptic number.

It is an amenable number.

21213211121321 is a deficient number, since it is larger than the sum of its proper divisors (2782880038039).

21213211121321 is a wasteful number, since it uses less digits than its factorization.

21213211121321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980232584.

The product of its digits is 288, while the sum is 23.

Adding to 21213211121321 its reverse (12312111231212), we get a palindrome (33525322352533).

The spelling of 21213211121321 in words is "twenty-one trillion, two hundred thirteen billion, two hundred eleven million, one hundred twenty-one thousand, three hundred twenty-one".