638828 has 6 divisors (see below), whose sum is σ = 1117956. Its totient is φ = 319412.

The previous prime is 638819. The next prime is 638839. The reversal of 638828 is 828836.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 638828.

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 as a sum of consecutive naturals, namely, 79850 + ... + 79857.

It is an arithmetic number, because the mean of its divisors is an integer number (186326).

2⁶³⁸⁸²⁸ is an apocalyptic number.

It is an amenable number.

638828 is a deficient number, since it is larger than the sum of its proper divisors (479128).

638828 is a wasteful number, since it uses less digits than its factorization.

638828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159711 (or 159709 counting only the distinct ones).

The product of its digits is 18432, while the sum is 35.

The square root of 638828 is about 799.2671643449. The cubic root of 638828 is about 86.1247513445.

The spelling of 638828 in words is "six hundred thirty-eight thousand, eight hundred twenty-eight".