2165604 has 72 divisors (see below), whose sum is σ = 6128640. Its totient is φ = 592704.

The previous prime is 2165599. The next prime is 2165617. The reversal of 2165604 is 4065612.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16989 + ... + 17115.

It is an arithmetic number, because the mean of its divisors is an integer number (85120).

2^2165604 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 2165604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3064320).

2165604 is an abundant number, since it is smaller than the sum of its proper divisors (3963036).

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

2165604 is a wasteful number, since it uses less digits than its factorization.

2165604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 2165604 is about 1471.5991301982. The cubic root of 2165604 is about 129.3777760846.

The spelling of 2165604 in words is "two million, one hundred sixty-five thousand, six hundred four".