638844 has 24 divisors (see below), whose sum is σ = 1505280. Its totient is φ = 210864.

The previous prime is 638839. The next prime is 638857. The reversal of 638844 is 448836.

It is a congruent number.

It is an unprimeable number.

638844 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1477 + ... + 1859.

It is an arithmetic number, because the mean of its divisors is an integer number (62720).

2⁶³⁸⁸⁴⁴ is an apocalyptic number.

It is an amenable number.

638844 is an abundant number, since it is smaller than the sum of its proper divisors (866436).

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

638844 is a wasteful number, since it uses less digits than its factorization.

638844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529 (or 527 counting only the distinct ones).

The product of its digits is 18432, while the sum is 33.

The square root of 638844 is about 799.2771734511. The cubic root of 638844 is about 86.1254703614.

The spelling of 638844 in words is "six hundred thirty-eight thousand, eight hundred forty-four".