1604242809 has 45 divisors (see below), whose sum is σ = 2542514793. Its totient is φ = 974729808.

The previous prime is 1604242763. The next prime is 1604242811. The reversal of 1604242809 is 9082424061.

The square root of 1604242809 is 40053.

It is a perfect power (a square), and thus also a powerful number.

1604242809 is a `hidden beast` number, since 1 + 604 + 2 + 42 + 8 + 0 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 795409209 + 808833600 = 28203^2 + 28440^2 .

It is not a de Polignac number, because 1604242809 - 2¹⁹ = 1603718521 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1604242309) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 20306832 + ... + 20306910.

Almost surely, 2^1604242809 is an apocalyptic number.

1604242809 is the 40053-rd square number.

1604242809 is the 20027-th centered octagonal number.

It is an amenable number.

1604242809 is a deficient number, since it is larger than the sum of its proper divisors (938271984).

1604242809 is an frugal number, since it uses more digits than its factorization.

1604242809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The cubic root of 1604242809 is about 1170.6400201990.

Multiplying 1604242809 by its sum of digits (36), we get a square (57752741124 = 240318²).

The spelling of 1604242809 in words is "one billion, six hundred four million, two hundred forty-two thousand, eight hundred nine".