1604404 has 6 divisors (see below), whose sum is σ = 2807714. Its totient is φ = 802200.

The previous prime is 1604399. The next prime is 1604413. The reversal of 1604404 is 4044061.

It can be written as a sum of positive squares in only one way, i.e., 996004 + 608400 = 998^2 + 780^2 .

It is a super-2 number, since 2×1604404² = 5148224390432, which contains 22 as substring.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 200547 + ... + 200554.

2^1604404 is an apocalyptic number.

It is an amenable number.

1604404 is a deficient number, since it is larger than the sum of its proper divisors (1203310).

1604404 is a wasteful number, since it uses less digits than its factorization.

1604404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401105 (or 401103 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 1604404 is about 1266.6507016538. The cubic root of 1604404 is about 117.0679226715.

Adding to 1604404 its reverse (4044061), we get a palindrome (5648465).

The spelling of 1604404 in words is "one million, six hundred four thousand, four hundred four".