638528 has 28 divisors (see below), whose sum is σ = 1383792. Its totient is φ = 289920.

The previous prime is 638527. The next prime is 638567. The reversal of 638528 is 825836.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 638494 and 638503.

It is not an unprimeable number, because it can be changed into a prime (638527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 251 + ... + 1157.

2⁶³⁸⁵²⁸ 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 638528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (691896).

638528 is an abundant number, since it is smaller than the sum of its proper divisors (745264).

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

638528 is a wasteful number, since it uses less digits than its factorization.

638528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930 (or 920 counting only the distinct ones).

The product of its digits is 11520, while the sum is 32.

The square root of 638528 is about 799.0794703908. The cubic root of 638528 is about 86.1112675528. Note that the first 3 decimals are identical.

The spelling of 638528 in words is "six hundred thirty-eight thousand, five hundred twenty-eight".