2001604889661 has 16 divisors (see below), whose sum is σ = 2875308590784. Its totient is φ = 1231238600064.

The previous prime is 2001604889617. The next prime is 2001604889699. The reversal of 2001604889661 is 1669884061002.

It is not a de Polignac number, because 2001604889661 - 2⁶ = 2001604889597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001604889461) 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, 10703091 + ... + 10888496.

It is an arithmetic number, because the mean of its divisors is an integer number (179706786924).

Almost surely, 2^{2001604889661} is an apocalyptic number.

It is an amenable number.

2001604889661 is a deficient number, since it is larger than the sum of its proper divisors (873703701123).

2001604889661 is a wasteful number, since it uses less digits than its factorization.

2001604889661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21593980.

The product of its (nonzero) digits is 995328, while the sum is 51.

The spelling of 2001604889661 in words is "two trillion, one billion, six hundred four million, eight hundred eighty-nine thousand, six hundred sixty-one".