21213613326321 has 36 divisors (see below), whose sum is σ = 33989541902316. Its totient is φ = 12736128038400.

The previous prime is 21213613326277. The next prime is 21213613326359. The reversal of 21213613326321 is 12362331631212.

21213613326321 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 3 + 6 + 1 + 3 + 326 + 321 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 5625961791921 + 15587651534400 = 2371911^2 + 3948120^2 .

It is not a de Polignac number, because 21213613326321 - 2²¹ = 21213611229169 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21213613326221) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 170024820 + ... + 170149541.

It is an arithmetic number, because the mean of its divisors is an integer number (944153941731).

Almost surely, 2^{21213613326321} is an apocalyptic number.

It is an amenable number.

21213613326321 is a deficient number, since it is larger than the sum of its proper divisors (12775928575995).

21213613326321 is a wasteful number, since it uses less digits than its factorization.

21213613326321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340174434 (or 340174418 counting only the distinct ones).

The product of its digits is 46656, while the sum is 36.

Adding to 21213613326321 its reverse (12362331631212), we get a palindrome (33575944957533).

The spelling of 21213613326321 in words is "twenty-one trillion, two hundred thirteen billion, six hundred thirteen million, three hundred twenty-six thousand, three hundred twenty-one".