638028 has 36 divisors (see below), whose sum is σ = 1659840. Its totient is φ = 206496.

The previous prime is 638023. The next prime is 638047. The reversal of 638028 is 820836.

638028 is a `hidden beast` number, since 638 + 0 + 28 = 666.

638028 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is a junction number, because it is equal to n+sod(n) for n = 637992 and 638010.

It is not an unprimeable number, because it can be changed into a prime (638023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1093 + ... + 1571.

2⁶³⁸⁰²⁸ 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 638028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (829920).

638028 is an abundant number, since it is smaller than the sum of its proper divisors (1021812).

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

638028 is a wasteful number, since it uses less digits than its factorization.

638028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 526 (or 521 counting only the distinct ones).

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

The square root of 638028 is about 798.7665491243. The cubic root of 638028 is about 86.0887851783.

The spelling of 638028 in words is "six hundred thirty-eight thousand, twenty-eight".