21321123320213 has 4 divisors (see below), whose sum is σ = 21326016857580. Its totient is φ = 21316229782848.

The previous prime is 21321123320191. The next prime is 21321123320327. The reversal of 21321123320213 is 31202332112312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18611484694609 + 2709638625604 = 4314103^2 + 1646098^2 .

It is a cyclic number.

It is not a de Polignac number, because 21321123320213 - 2¹⁴ = 21321123303829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321123380213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2446762148 + ... + 2446770861.

It is an arithmetic number, because the mean of its divisors is an integer number (5331504214395).

Almost surely, 2^{21321123320213} is an apocalyptic number.

It is an amenable number.

21321123320213 is a deficient number, since it is larger than the sum of its proper divisors (4893537367).

21321123320213 is an equidigital number, since it uses as much as digits as its factorization.

21321123320213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4893537366.

The product of its (nonzero) digits is 2592, while the sum is 26.

Adding to 21321123320213 its reverse (31202332112312), we get a palindrome (52523455432525).

The spelling of 21321123320213 in words is "twenty-one trillion, three hundred twenty-one billion, one hundred twenty-three million, three hundred twenty thousand, two hundred thirteen".