644048904 has 16 divisors (see below), whose sum is σ = 1610122320. Its totient is φ = 214682960.

The previous prime is 644048887. The next prime is 644048929. The reversal of 644048904 is 409840446.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13417662 + ... + 13417709.

It is an arithmetic number, because the mean of its divisors is an integer number (100632645).

Almost surely, 2^644048904 is an apocalyptic number.

It is an amenable number.

644048904 is an abundant number, since it is smaller than the sum of its proper divisors (966073416).

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

644048904 is a wasteful number, since it uses less digits than its factorization.

644048904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26835380 (or 26835376 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 39.

The square root of 644048904 is about 25378.1186063900. The cubic root of 644048904 is about 863.5873694103.

The spelling of 644048904 in words is "six hundred forty-four million, forty-eight thousand, nine hundred four".