638693204 has 6 divisors (see below), whose sum is σ = 1117713114. Its totient is φ = 319346600.

The previous prime is 638693201. The next prime is 638693243. The reversal of 638693204 is 402396836.

It can be written as a sum of positive squares in only one way, i.e., 386201104 + 252492100 = 19652^2 + 15890^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638693201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79836647 + ... + 79836654.

It is an arithmetic number, because the mean of its divisors is an integer number (186285519).

Almost surely, 2^638693204 is an apocalyptic number.

It is an amenable number.

638693204 is a deficient number, since it is larger than the sum of its proper divisors (479019910).

638693204 is a wasteful number, since it uses less digits than its factorization.

638693204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159673305 (or 159673303 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 41.

The square root of 638693204 is about 25272.3802598805. The cubic root of 638693204 is about 861.1869332956.

The spelling of 638693204 in words is "six hundred thirty-eight million, six hundred ninety-three thousand, two hundred four".