638825 has 24 divisors (see below), whose sum is σ = 910656. Its totient is φ = 440000.

The previous prime is 638819. The next prime is 638839. The reversal of 638825 is 528836.

It is not a de Polignac number, because 638825 - 2¹⁶ = 573289 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 638791 and 638800.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 6275 + ... + 6375.

It is an arithmetic number, because the mean of its divisors is an integer number (37944).

2⁶³⁸⁸²⁵ is an apocalyptic number.

It is an amenable number.

638825 is a deficient number, since it is larger than the sum of its proper divisors (271831).

638825 is a wasteful number, since it uses less digits than its factorization.

638825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 140 counting only the distinct ones).

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

The square root of 638825 is about 799.2652876236. The cubic root of 638825 is about 86.1246165274.

It can be divided in two parts, 63 and 8825, that added together give a palindrome (8888).

The spelling of 638825 in words is "six hundred thirty-eight thousand, eight hundred twenty-five".