638311 has 4 divisors (see below), whose sum is σ = 640224. Its totient is φ = 636400.

The previous prime is 638303. The next prime is 638317. The reversal of 638311 is 113836.

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 638311 - 2³ = 638303 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638317) 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, 310 + ... + 1171.

It is an arithmetic number, because the mean of its divisors is an integer number (160056).

2⁶³⁸³¹¹ is an apocalyptic number.

638311 is a deficient number, since it is larger than the sum of its proper divisors (1913).

638311 is a wasteful number, since it uses less digits than its factorization.

638311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1912.

The product of its digits is 432, while the sum is 22.

The square root of 638311 is about 798.9436776144. The cubic root of 638311 is about 86.1015116443.

It can be divided in two parts, 638 and 311, that added together give a palindrome (949).

The spelling of 638311 in words is "six hundred thirty-eight thousand, three hundred eleven".