21330241321 has 4 divisors (see below), whose sum is σ = 21337892100. Its totient is φ = 21322590544.

The previous prime is 21330241279. The next prime is 21330241357. The reversal of 21330241321 is 12314203312.

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 4955456025 + 16374785296 = 70395^2 + 127964^2 .

It is a cyclic number.

It is not a de Polignac number, because 21330241321 - 2¹⁵ = 21330208553 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21330241292 and 21330241301.

It is not an unprimeable number, because it can be changed into a prime (21330241421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3821206 + ... + 3826783.

It is an arithmetic number, because the mean of its divisors is an integer number (5334473025).

Almost surely, 2^21330241321 is an apocalyptic number.

It is an amenable number.

21330241321 is a deficient number, since it is larger than the sum of its proper divisors (7650779).

21330241321 is an equidigital number, since it uses as much as digits as its factorization.

21330241321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7650778.

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 21330241321 its reverse (12314203312), we get a palindrome (33644444633).

The spelling of 21330241321 in words is "twenty-one billion, three hundred thirty million, two hundred forty-one thousand, three hundred twenty-one".