16579605621 has 4 divisors (see below), whose sum is σ = 22106140832. Its totient is φ = 11053070412.

The previous prime is 16579605607. The next prime is 16579605661. The reversal of 16579605621 is 12650697561.

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 not a de Polignac number, because 16579605621 - 2²⁶ = 16512496757 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16579605661) 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, 2763267601 + ... + 2763267606.

It is an arithmetic number, because the mean of its divisors is an integer number (5526535208).

Almost surely, 2^16579605621 is an apocalyptic number.

It is an amenable number.

16579605621 is a deficient number, since it is larger than the sum of its proper divisors (5526535211).

16579605621 is an equidigital number, since it uses as much as digits as its factorization.

16579605621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5526535210.

The product of its (nonzero) digits is 680400, while the sum is 48.

The spelling of 16579605621 in words is "sixteen billion, five hundred seventy-nine million, six hundred five thousand, six hundred twenty-one".