638870 has 16 divisors (see below), whose sum is σ = 1190160. Its totient is φ = 246624.

The previous prime is 638861. The next prime is 638893. The reversal of 638870 is 78836.

It is a Curzon number.

It is a congruent number.

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, 812 + ... + 1391.

It is an arithmetic number, because the mean of its divisors is an integer number (74385).

2⁶³⁸⁸⁷⁰ is an apocalyptic number.

638870 is a deficient number, since it is larger than the sum of its proper divisors (551290).

638870 is a wasteful number, since it uses less digits than its factorization.

638870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2239.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 638870 is about 799.2934379813. The cubic root of 638870 is about 86.1266387384.

The spelling of 638870 in words is "six hundred thirty-eight thousand, eight hundred seventy".