638873 has 4 divisors (see below), whose sum is σ = 647040. Its totient is φ = 630708.

The previous prime is 638861. The next prime is 638893. The reversal of 638873 is 378836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 638873 - 2⁴ = 638857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638893) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3965 + ... + 4122.

It is an arithmetic number, because the mean of its divisors is an integer number (161760).

2⁶³⁸⁸⁷³ is an apocalyptic number.

It is an amenable number.

638873 is a deficient number, since it is larger than the sum of its proper divisors (8167).

638873 is an equidigital number, since it uses as much as digits as its factorization.

638873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8166.

The product of its digits is 24192, while the sum is 35.

The square root of 638873 is about 799.2953146366. The cubic root of 638873 is about 86.1267735491.

The spelling of 638873 in words is "six hundred thirty-eight thousand, eight hundred seventy-three".