638204 has 24 divisors (see below), whose sum is σ = 1333248. Its totient is φ = 261360.

The previous prime is 638201. The next prime is 638233. The reversal of 638204 is 402836.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 638204.

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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149 + ... + 1139.

It is an arithmetic number, because the mean of its divisors is an integer number (55552).

2⁶³⁸²⁰⁴ 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 638204, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (666624).

638204 is an abundant number, since it is smaller than the sum of its proper divisors (695044).

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

638204 is a wasteful number, since it uses less digits than its factorization.

638204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1025 (or 1023 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 638204 is about 798.8767113892. The cubic root of 638204 is about 86.0967003133.

The spelling of 638204 in words is "six hundred thirty-eight thousand, two hundred four".