638529 has 4 divisors (see below), whose sum is σ = 851376. Its totient is φ = 425684.

The previous prime is 638527. The next prime is 638567. The reversal of 638529 is 925836.

It is a happy number.

638529 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 638529 - 2¹ = 638527 is a prime.

It is a D-number.

It is an alternating number because its digits alternate between even and odd.

638529 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 638529.

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, 106419 + ... + 106424.

It is an arithmetic number, because the mean of its divisors is an integer number (212844).

2⁶³⁸⁵²⁹ is an apocalyptic number.

It is an amenable number.

638529 is a deficient number, since it is larger than the sum of its proper divisors (212847).

638529 is a wasteful number, since it uses less digits than its factorization.

638529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212846.

The product of its digits is 12960, while the sum is 33.

The square root of 638529 is about 799.0800961105. The cubic root of 638529 is about 86.1113125058. Note that the first 3 decimals are identical.

The spelling of 638529 in words is "six hundred thirty-eight thousand, five hundred twenty-nine".