16506423321 has 4 divisors (see below), whose sum is σ = 22008564432. Its totient is φ = 11004282212.

The previous prime is 16506423301. The next prime is 16506423341. The reversal of 16506423321 is 12332460561.

16506423321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 an interprime number because it is at equal distance from previous prime (16506423301) and next prime (16506423341).

It is a cyclic number.

It is not a de Polignac number, because 16506423321 - 2⁵ = 16506423289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16506423301) 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, 2751070551 + ... + 2751070556.

It is an arithmetic number, because the mean of its divisors is an integer number (5502141108).

Almost surely, 2^16506423321 is an apocalyptic number.

It is an amenable number.

16506423321 is a deficient number, since it is larger than the sum of its proper divisors (5502141111).

16506423321 is an equidigital number, since it uses as much as digits as its factorization.

16506423321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5502141110.

The product of its (nonzero) digits is 25920, while the sum is 33.

Adding to 16506423321 its reverse (12332460561), we get a palindrome (28838883882).

The spelling of 16506423321 in words is "sixteen billion, five hundred six million, four hundred twenty-three thousand, three hundred twenty-one".