16533611321 has 4 divisors (see below), whose sum is σ = 16534438992. Its totient is φ = 16532783652.

The previous prime is 16533611299. The next prime is 16533611323. The reversal of 16533611321 is 12311633561.

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 16533611321 - 2¹⁸ = 16533349177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16533611323) 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, 383111 + ... + 424076.

It is an arithmetic number, because the mean of its divisors is an integer number (4133609748).

Almost surely, 2^16533611321 is an apocalyptic number.

It is an amenable number.

16533611321 is a deficient number, since it is larger than the sum of its proper divisors (827671).

16533611321 is an equidigital number, since it uses as much as digits as its factorization.

16533611321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 827670.

The product of its digits is 9720, while the sum is 32.

The spelling of 16533611321 in words is "sixteen billion, five hundred thirty-three million, six hundred eleven thousand, three hundred twenty-one".