16604351661 has 16 divisors (see below), whose sum is σ = 22395761280. Its totient is φ = 10941342720.

The previous prime is 16604351629. The next prime is 16604351677. The reversal of 16604351661 is 16615340661.

It is not a de Polignac number, because 16604351661 - 2⁵ = 16604351629 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16604351611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 888136 + ... + 906638.

It is an arithmetic number, because the mean of its divisors is an integer number (1399735080).

Almost surely, 2^16604351661 is an apocalyptic number.

It is an amenable number.

16604351661 is a deficient number, since it is larger than the sum of its proper divisors (5791409619).

16604351661 is a wasteful number, since it uses less digits than its factorization.

16604351661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21956.

The product of its (nonzero) digits is 77760, while the sum is 39.

The spelling of 16604351661 in words is "sixteen billion, six hundred four million, three hundred fifty-one thousand, six hundred sixty-one".