638525 has 6 divisors (see below), whose sum is σ = 791802. Its totient is φ = 510800.

The previous prime is 638501. The next prime is 638527. The reversal of 638525 is 525836.

It can be written as a sum of positive squares in 3 ways, for example, as 31684 + 606841 = 178^2 + 779^2 .

It is not a de Polignac number, because 638525 - 2⁸ = 638269 is a prime.

It is a d-powerful number, because it can be written as 6³ + 3 + 5⁵ + 8⁵ + 2¹⁹ + 5⁷ .

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

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12746 + ... + 12795.

It is an arithmetic number, because the mean of its divisors is an integer number (131967).

2⁶³⁸⁵²⁵ is an apocalyptic number.

It is an amenable number.

638525 is a deficient number, since it is larger than the sum of its proper divisors (153277).

638525 is a wasteful number, since it uses less digits than its factorization.

638525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25551 (or 25546 counting only the distinct ones).

The product of its digits is 7200, while the sum is 29.

The square root of 638525 is about 799.0775932286. The cubic root of 638525 is about 86.1111326936. Note that the first 4 decimals are identical.

The spelling of 638525 in words is "six hundred thirty-eight thousand, five hundred twenty-five".