1604664 has 128 divisors (see below), whose sum is σ = 5184000. Its totient is φ = 456192.

The previous prime is 1604651. The next prime is 1604711. The reversal of 1604664 is 4664061.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 6.

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69757 + ... + 69779.

It is an arithmetic number, because the mean of its divisors is an integer number (40500).

2^1604664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1604664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2592000).

1604664 is an abundant number, since it is smaller than the sum of its proper divisors (3579336).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1604664 is a wasteful number, since it uses less digits than its factorization.

1604664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 1604664 is about 1266.7533303686. The cubic root of 1604664 is about 117.0742461029.

It can be divided in two parts, 16046 and 64, that added together give a triangular number (16110 = T₁₇₉).

The spelling of 1604664 in words is "one million, six hundred four thousand, six hundred sixty-four".