638279 has 4 divisors (see below), whose sum is σ = 650376. Its totient is φ = 626184.

The previous prime is 638269. The next prime is 638303. The reversal of 638279 is 972836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 638279 - 2⁴ = 638263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638269) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5969 + ... + 6074.

It is an arithmetic number, because the mean of its divisors is an integer number (162594).

2⁶³⁸²⁷⁹ is an apocalyptic number.

638279 is a deficient number, since it is larger than the sum of its proper divisors (12097).

638279 is a wasteful number, since it uses less digits than its factorization.

638279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12096.

The product of its digits is 18144, while the sum is 35.

The square root of 638279 is about 798.9236509204. The cubic root of 638279 is about 86.1000727979.

It can be divided in two parts, 63827 and 9, that added together give a palindrome (63836).

The spelling of 638279 in words is "six hundred thirty-eight thousand, two hundred seventy-nine".