638447884 has 6 divisors (see below), whose sum is σ = 1117283804. Its totient is φ = 319223940.

The previous prime is 638447863. The next prime is 638447897. The reversal of 638447884 is 488744836.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79805982 + ... + 79805989.

Almost surely, 2^638447884 is an apocalyptic number.

It is an amenable number.

638447884 is a deficient number, since it is larger than the sum of its proper divisors (478835920).

638447884 is a wasteful number, since it uses less digits than its factorization.

638447884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159611975 (or 159611973 counting only the distinct ones).

The product of its digits is 4128768, while the sum is 52.

The square root of 638447884 is about 25267.5262738559. The cubic root of 638447884 is about 861.0766594679.

The spelling of 638447884 in words is "six hundred thirty-eight million, four hundred forty-seven thousand, eight hundred eighty-four".