638218804 has 12 divisors (see below), whose sum is σ = 1117222624. Its totient is φ = 319012344.

The previous prime is 638218741. The next prime is 638218813. The reversal of 638218804 is 408812836.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8304 + ... + 36679.

Almost surely, 2^638218804 is an apocalyptic number.

It is an amenable number.

638218804 is a deficient number, since it is larger than the sum of its proper divisors (479003820).

638218804 is a wasteful number, since it uses less digits than its factorization.

638218804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48534 (or 48532 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 40.

The square root of 638218804 is about 25262.9927759955. The cubic root of 638218804 is about 860.9736601769.

The spelling of 638218804 in words is "six hundred thirty-eight million, two hundred eighteen thousand, eight hundred four".