638808 has 32 divisors (see below), whose sum is σ = 1636800. Its totient is φ = 207648.

The previous prime is 638801. The next prime is 638819. The reversal of 638808 is 808836.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 638808.

It is not an unprimeable number, because it can be changed into a prime (638801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 723 + ... + 1341.

It is an arithmetic number, because the mean of its divisors is an integer number (51150).

2⁶³⁸⁸⁰⁸ 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 638808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (818400).

638808 is an abundant number, since it is smaller than the sum of its proper divisors (997992).

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

638808 is a wasteful number, since it uses less digits than its factorization.

638808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671 (or 667 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 638808 is about 799.2546527860. The cubic root of 638808 is about 86.1238525564.

The spelling of 638808 in words is "six hundred thirty-eight thousand, eight hundred eight".