638504 has 8 divisors (see below), whose sum is σ = 1197210. Its totient is φ = 319248.

The previous prime is 638501. The next prime is 638527. The reversal of 638504 is 405836.

638504 = 91² + 92² + ... + 138².

638504 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 357604 + 280900 = 598^2 + 530^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (638501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39899 + ... + 39914.

2⁶³⁸⁵⁰⁴ is an apocalyptic number.

It is an amenable number.

638504 is a deficient number, since it is larger than the sum of its proper divisors (558706).

638504 is a wasteful number, since it uses less digits than its factorization.

638504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79819 (or 79815 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 638504 is about 799.0644529698. The cubic root of 638504 is about 86.1101886670.

The spelling of 638504 in words is "six hundred thirty-eight thousand, five hundred four".