638672718 has 16 divisors (see below), whose sum is σ = 1289748096. Its totient is φ = 210823800.

The previous prime is 638672701. The next prime is 638672729. The reversal of 638672718 is 817276836.

638672718 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 516108 + ... + 517343.

It is an arithmetic number, because the mean of its divisors is an integer number (80609256).

Almost surely, 2^638672718 is an apocalyptic number.

638672718 is an abundant number, since it is smaller than the sum of its proper divisors (651075378).

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

638672718 is a wasteful number, since it uses less digits than its factorization.

638672718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1033559.

The product of its digits is 677376, while the sum is 48.

The square root of 638672718 is about 25271.9749525042. The cubic root of 638672718 is about 861.1777257116.

The spelling of 638672718 in words is "six hundred thirty-eight million, six hundred seventy-two thousand, seven hundred eighteen".