1604671605 has 12 divisors (see below), whose sum is σ = 2781430860. Its totient is φ = 855824832.

The previous prime is 1604671597. The next prime is 1604671643. The reversal of 1604671605 is 5061764061.

1604671605 is a `hidden beast` number, since 1 + 6 + 0 + 46 + 7 + 1 + 605 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1142507601 + 462164004 = 33801^2 + 21498^2 .

It is not a de Polignac number, because 1604671605 - 2³ = 1604671597 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1604671605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17829640 + ... + 17829729.

It is an arithmetic number, because the mean of its divisors is an integer number (231785905).

Almost surely, 2^1604671605 is an apocalyptic number.

1604671605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1604671605 is a deficient number, since it is larger than the sum of its proper divisors (1176759255).

1604671605 is a wasteful number, since it uses less digits than its factorization.

1604671605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35659380 (or 35659377 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 1604671605 is about 40058.3524998221. The cubic root of 1604671605 is about 1170.7443105301.

The spelling of 1604671605 in words is "one billion, six hundred four million, six hundred seventy-one thousand, six hundred five".