638704 has 40 divisors (see below), whose sum is σ = 1428480. Its totient is φ = 273600.

The previous prime is 638699. The next prime is 638717. The reversal of 638704 is 407836.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3249 + ... + 3439.

It is an arithmetic number, because the mean of its divisors is an integer number (35712).

2⁶³⁸⁷⁰⁴ 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 638704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (714240).

638704 is an abundant number, since it is smaller than the sum of its proper divisors (789776).

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

638704 is a wasteful number, since it uses less digits than its factorization.

638704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229 (or 223 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 638704 is about 799.1895895218. The cubic root of 638704 is about 86.1191785558.

The spelling of 638704 in words is "six hundred thirty-eight thousand, seven hundred four".