638718 has 8 divisors (see below), whose sum is σ = 1277448. Its totient is φ = 212904.

The previous prime is 638717. The next prime is 638719. The reversal of 638718 is 817836.

It is an interprime number because it is at equal distance from previous prime (638717) and next prime (638719).

It is a sphenic number, since it is the product of 3 distinct primes.

638718 is an admirable number.

It is a plaindrome in base 14.

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 638718.

It is not an unprimeable number, because it can be changed into a prime (638717) 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, 53221 + ... + 53232.

It is an arithmetic number, because the mean of its divisors is an integer number (159681).

2⁶³⁸⁷¹⁸ is an apocalyptic number.

638718 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638718 is a wasteful number, since it uses less digits than its factorization.

638718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106458.

The product of its digits is 8064, while the sum is 33.

The square root of 638718 is about 799.1983483466. The cubic root of 638718 is about 86.1198077778.

The spelling of 638718 in words is "six hundred thirty-eight thousand, seven hundred eighteen".