644327004 has 24 divisors (see below), whose sum is σ = 1505875840. Its totient is φ = 214426224.

The previous prime is 644327003. The next prime is 644327009. The reversal of 644327004 is 400723446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644327003) 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, 35944 + ... + 50799.

Almost surely, 2^644327004 is an apocalyptic number.

It is an amenable number.

644327004 is an abundant number, since it is smaller than the sum of its proper divisors (861548836).

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

644327004 is a wasteful number, since it uses less digits than its factorization.

644327004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87369 (or 87367 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 30.

The square root of 644327004 is about 25383.5971446129. The cubic root of 644327004 is about 863.7116503910.

The spelling of 644327004 in words is "six hundred forty-four million, three hundred twenty-seven thousand, four".