1604905 has 8 divisors (see below), whose sum is σ = 1952712. Its totient is φ = 1266048.

The previous prime is 1604857. The next prime is 1604923. The reversal of 1604905 is 5094061.

It can be written as a sum of positive squares in 4 ways, for example, as 184041 + 1420864 = 429^2 + 1192^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1604905 - 2¹¹ = 1602857 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1604905.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1834 + ... + 2563.

It is an arithmetic number, because the mean of its divisors is an integer number (244089).

2^1604905 is an apocalyptic number.

It is an amenable number.

1604905 is a deficient number, since it is larger than the sum of its proper divisors (347807).

1604905 is an equidigital number, since it uses as much as digits as its factorization.

1604905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4475.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 1604905 is about 1266.8484518679. The cubic root of 1604905 is about 117.0801068274.

Adding to 1604905 its reverse (5094061), we get a palindrome (6698966).

The spelling of 1604905 in words is "one million, six hundred four thousand, nine hundred five".