644055488 has 14 divisors (see below), whose sum is σ = 1278047736. Its totient is φ = 322027712.

The previous prime is 644055463. The next prime is 644055491. The reversal of 644055488 is 884550446.

It is a happy number.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 5031620 + ... + 5031747.

It is an arithmetic number, because the mean of its divisors is an integer number (91289124).

Almost surely, 2^644055488 is an apocalyptic number.

It is an amenable number.

644055488 is a deficient number, since it is larger than the sum of its proper divisors (633992248).

644055488 is a wasteful number, since it uses less digits than its factorization.

644055488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10063379 (or 10063369 counting only the distinct ones).

The product of its (nonzero) digits is 614400, while the sum is 44.

The square root of 644055488 is about 25378.2483241062. The cubic root of 644055488 is about 863.5903121681.

The spelling of 644055488 in words is "six hundred forty-four million, fifty-five thousand, four hundred eighty-eight".