638544 has 40 divisors (see below), whose sum is σ = 1687392. Its totient is φ = 208000.

The previous prime is 638527. The next prime is 638567. The reversal of 638544 is 445836.

638544 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an Ulam number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 638544.

It is an unprimeable number.

638544 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, 2419 + ... + 2669.

2⁶³⁸⁵⁴⁴ 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 638544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (843696).

638544 is an abundant number, since it is smaller than the sum of its proper divisors (1048848).

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

638544 is a wasteful number, since it uses less digits than its factorization.

638544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315 (or 309 counting only the distinct ones).

The product of its digits is 11520, while the sum is 30.

The square root of 638544 is about 799.0894818479. The cubic root of 638544 is about 86.1119867950. Note that the first 3 decimals are identical.

The spelling of 638544 in words is "six hundred thirty-eight thousand, five hundred forty-four".