638368 has 12 divisors (see below), whose sum is σ = 1256850. Its totient is φ = 319168.

The previous prime is 638359. The next prime is 638371. The reversal of 638368 is 863836.

638368 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 620944 + 17424 = 788^2 + 132^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9943 + ... + 10006.

2⁶³⁸³⁶⁸ is an apocalyptic number.

It is an amenable number.

638368 is a deficient number, since it is larger than the sum of its proper divisors (618482).

638368 is a wasteful number, since it uses less digits than its factorization.

638368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19959 (or 19951 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

The square root of 638368 is about 798.9793489196. The cubic root of 638368 is about 86.1040744703.

The spelling of 638368 in words is "six hundred thirty-eight thousand, three hundred sixty-eight".