638824 has 16 divisors (see below), whose sum is σ = 1224000. Its totient is φ = 312432.

The previous prime is 638819. The next prime is 638839. The reversal of 638824 is 428836.

It is a happy number.

It is a super-2 number, since 2×638824² = 816192205952, which contains 22 as substring.

It is an unprimeable number.

638824 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 3 ways as a sum of consecutive naturals, for example, 474 + ... + 1225.

It is an arithmetic number, because the mean of its divisors is an integer number (76500).

2⁶³⁸⁸²⁴ is an apocalyptic number.

It is an amenable number.

638824 is a deficient number, since it is larger than the sum of its proper divisors (585176).

638824 is a wasteful number, since it uses less digits than its factorization.

638824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1752 (or 1748 counting only the distinct ones).

The product of its digits is 9216, while the sum is 31.

The square root of 638824 is about 799.2646620488. The cubic root of 638824 is about 86.1245715883.

The spelling of 638824 in words is "six hundred thirty-eight thousand, eight hundred twenty-four".