640068718 has 8 divisors (see below), whose sum is σ = 991074240. Its totient is φ = 309710640.

The previous prime is 640068707. The next prime is 640068719. The reversal of 640068718 is 817860046.

640068718 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640068719) 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, 5161783 + ... + 5161906.

It is an arithmetic number, because the mean of its divisors is an integer number (123884280).

Almost surely, 2^640068718 is an apocalyptic number.

640068718 is a deficient number, since it is larger than the sum of its proper divisors (351005522).

640068718 is a wasteful number, since it uses less digits than its factorization.

640068718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10323722.

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 640068718 is about 25299.5794036186. The cubic root of 640068718 is about 861.8047183345.

The spelling of 640068718 in words is "six hundred forty million, sixty-eight thousand, seven hundred eighteen".