16534357921 has 4 divisors (see below), whose sum is σ = 17253243072. Its totient is φ = 15815472772.

The previous prime is 16534357907. The next prime is 16534358041. The reversal of 16534357921 is 12975343561.

16534357921 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 a cyclic number.

It is not a de Polignac number, because 16534357921 - 2¹⁵ = 16534325153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16534357121) 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, 359442541 + ... + 359442586.

It is an arithmetic number, because the mean of its divisors is an integer number (4313310768).

Almost surely, 2^16534357921 is an apocalyptic number.

It is an amenable number.

16534357921 is a deficient number, since it is larger than the sum of its proper divisors (718885151).

16534357921 is an equidigital number, since it uses as much as digits as its factorization.

16534357921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718885150.

The product of its digits is 680400, while the sum is 46.

The spelling of 16534357921 in words is "sixteen billion, five hundred thirty-four million, three hundred fifty-seven thousand, nine hundred twenty-one".