21324215321 has 4 divisors (see below), whose sum is σ = 21359346432. Its totient is φ = 21289084212.

The previous prime is 21324215279. The next prime is 21324215329. The reversal of 21324215321 is 12351242312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21324215321 - 2³⁰ = 20250473497 is a prime.

It is a super-2 number, since 2×21324215321² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21324215329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17564645 + ... + 17565858.

It is an arithmetic number, because the mean of its divisors is an integer number (5339836608).

Almost surely, 2^21324215321 is an apocalyptic number.

It is an amenable number.

21324215321 is a deficient number, since it is larger than the sum of its proper divisors (35131111).

21324215321 is an equidigital number, since it uses as much as digits as its factorization.

21324215321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35131110.

The product of its digits is 2880, while the sum is 26.

Adding to 21324215321 its reverse (12351242312), we get a palindrome (33675457633).

The spelling of 21324215321 in words is "twenty-one billion, three hundred twenty-four million, two hundred fifteen thousand, three hundred twenty-one".