638871 has 16 divisors (see below), whose sum is σ = 912384. Its totient is φ = 396704.

The previous prime is 638861. The next prime is 638893. The reversal of 638871 is 178836.

It is not a de Polignac number, because 638871 - 2⁵ = 638839 is a prime.

638871 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3145 + ... + 3341.

It is an arithmetic number, because the mean of its divisors is an integer number (57024).

2⁶³⁸⁸⁷¹ is an apocalyptic number.

638871 is a deficient number, since it is larger than the sum of its proper divisors (273513).

638871 is a wasteful number, since it uses less digits than its factorization.

638871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270.

The product of its digits is 8064, while the sum is 33.

The square root of 638871 is about 799.2940635336. The cubic root of 638871 is about 86.1266836753.

The spelling of 638871 in words is "six hundred thirty-eight thousand, eight hundred seventy-one".