638705 has 8 divisors (see below), whose sum is σ = 772800. Its totient is φ = 506736.

The previous prime is 638699. The next prime is 638717. The reversal of 638705 is 507836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 638705 - 2⁴ = 638689 is a prime.

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

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 7 ways as a sum of consecutive naturals, for example, 236 + ... + 1154.

It is an arithmetic number, because the mean of its divisors is an integer number (96600).

2⁶³⁸⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

638705 is a deficient number, since it is larger than the sum of its proper divisors (134095).

638705 is a wasteful number, since it uses less digits than its factorization.

638705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 638705 is about 799.1902151553. The cubic root of 638705 is about 86.1192235006.

The spelling of 638705 in words is "six hundred thirty-eight thousand, seven hundred five".