638318 has 4 divisors (see below), whose sum is σ = 957480. Its totient is φ = 319158.

The previous prime is 638317. The next prime is 638327. The reversal of 638318 is 813836.

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

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 638318.

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 as a sum of consecutive naturals, namely, 159578 + ... + 159581.

It is an arithmetic number, because the mean of its divisors is an integer number (239370).

2⁶³⁸³¹⁸ is an apocalyptic number.

638318 is a deficient number, since it is larger than the sum of its proper divisors (319162).

638318 is a wasteful number, since it uses less digits than its factorization.

638318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319161.

The product of its digits is 3456, while the sum is 29.

The square root of 638318 is about 798.9480583868. The cubic root of 638318 is about 86.1018263855.

The spelling of 638318 in words is "six hundred thirty-eight thousand, three hundred eighteen".