644461004 has 36 divisors (see below), whose sum is σ = 1243443600. Its totient is φ = 292042080.

The previous prime is 644460977. The next prime is 644461031. The reversal of 644461004 is 400164446.

644461004 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (644460977) and next prime (644461031).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 171902 + ... + 175610.

It is an arithmetic number, because the mean of its divisors is an integer number (34540100).

Almost surely, 2^644461004 is an apocalyptic number.

It is an amenable number.

644461004 is a deficient number, since it is larger than the sum of its proper divisors (598982596).

644461004 is a wasteful number, since it uses less digits than its factorization.

644461004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4094 (or 4081 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 29.

The square root of 644461004 is about 25386.2365072100. The cubic root of 644461004 is about 863.7715213044.

The spelling of 644461004 in words is "six hundred forty-four million, four hundred sixty-one thousand, four".