638208 has 54 divisors (see below), whose sum is σ = 1846754. Its totient is φ = 211968.

The previous prime is 638201. The next prime is 638233. The reversal of 638208 is 802836.

638208 is a `hidden beast` number, since 638 + 20 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 451584 + 186624 = 672^2 + 432^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638201) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2166 + ... + 2442.

2⁶³⁸²⁰⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (923377).

638208 is an abundant number, since it is smaller than the sum of its proper divisors (1208546).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638208 is a wasteful number, since it uses less digits than its factorization.

638208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299 (or 282 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 638208 is about 798.8792149005. The cubic root of 638208 is about 86.0968801858.

The spelling of 638208 in words is "six hundred thirty-eight thousand, two hundred eight".