4004000644 has 24 divisors (see below), whose sum is σ = 8429476160. Its totient is φ = 1625684256.

The previous prime is 4004000617. The next prime is 4004000647. The reversal of 4004000644 is 4460004004.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (4004000647) 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, 3762627 + ... + 3763690.

Almost surely, 2^4004000644 is an apocalyptic number.

It is an amenable number.

4004000644 is an abundant number, since it is smaller than the sum of its proper divisors (4425475516).

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

4004000644 is a wasteful number, since it uses less digits than its factorization.

4004000644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7526347 (or 7526345 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

The square root of 4004000644 is about 63277.1731669486. The cubic root of 4004000644 is about 1587.9300945060.

Adding to 4004000644 its reverse (4460004004), we get a palindrome (8464004648).

The spelling of 4004000644 in words is "four billion, four million, six hundred forty-four", and thus it is an aban number.