318639 has 4 divisors (see below), whose sum is σ = 424856. Its totient is φ = 212424.

The previous prime is 318629. The next prime is 318641. The reversal of 318639 is 936813.

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

It is not a de Polignac number, because 318639 - 2⁹ = 318127 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (318629) 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, 53104 + ... + 53109.

It is an arithmetic number, because the mean of its divisors is an integer number (106214).

2³¹⁸⁶³⁹ is an apocalyptic number.

318639 is a deficient number, since it is larger than the sum of its proper divisors (106217).

318639 is a wasteful number, since it uses less digits than its factorization.

318639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106216.

The product of its digits is 3888, while the sum is 30.

The square root of 318639 is about 564.4811777199. The cubic root of 318639 is about 68.3019301803.

The spelling of 318639 in words is "three hundred eighteen thousand, six hundred thirty-nine".