21313231322321 has 4 divisors (see below), whose sum is σ = 21335595679332. Its totient is φ = 21290866965312.

The previous prime is 21313231322311. The next prime is 21313231322323. The reversal of 21313231322321 is 12322313231312.

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 16344393552400 + 4968837769921 = 4042820^2 + 2229089^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21313231322321 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21313231322323) 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, 11182177076 + ... + 11182178981.

It is an arithmetic number, because the mean of its divisors is an integer number (5333898919833).

Almost surely, 2^{21313231322321} is an apocalyptic number.

It is an amenable number.

21313231322321 is a deficient number, since it is larger than the sum of its proper divisors (22364357011).

21313231322321 is an equidigital number, since it uses as much as digits as its factorization.

21313231322321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22364357010.

The product of its digits is 7776, while the sum is 29.

Adding to 21313231322321 its reverse (12322313231312), we get a palindrome (33635544553633).

The spelling of 21313231322321 in words is "twenty-one trillion, three hundred thirteen billion, two hundred thirty-one million, three hundred twenty-two thousand, three hundred twenty-one".