1605644004 has 24 divisors (see below), whose sum is σ = 3771318208. Its totient is φ = 531669600.

The previous prime is 1605644003. The next prime is 1605644021. The reversal of 1605644004 is 4004465061.

It is not an unprimeable number, because it can be changed into a prime (1605644003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 441247 + ... + 444870.

Almost surely, 2^1605644004 is an apocalyptic number.

It is an amenable number.

1605644004 is an abundant number, since it is smaller than the sum of its proper divisors (2165674204).

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

1605644004 is a wasteful number, since it uses less digits than its factorization.

1605644004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 886275 (or 886273 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 1605644004 is about 40070.4879431234. The cubic root of 1605644004 is about 1170.9807453486.

The spelling of 1605644004 in words is "one billion, six hundred five million, six hundred forty-four thousand, four".