639068697808 has 20 divisors (see below), whose sum is σ = 1238209346628. Its totient is φ = 319530801920.

The previous prime is 639068697793. The next prime is 639068697823. The reversal of 639068697808 is 808796860936.

639068697808 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (639068697793) and next prime (639068697823).

It can be written as a sum of positive squares in 2 ways, for example, as 369989959824 + 269078737984 = 608268^2 + 518728^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1853238 + ... + 2170858.

Almost surely, 2^639068697808 is an apocalyptic number.

It is an amenable number.

639068697808 is a deficient number, since it is larger than the sum of its proper divisors (599140648820).

639068697808 is a wasteful number, since it uses less digits than its factorization.

639068697808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443382 (or 443376 counting only the distinct ones).

The product of its (nonzero) digits is 188116992, while the sum is 70.

The spelling of 639068697808 in words is "six hundred thirty-nine billion, sixty-eight million, six hundred ninety-seven thousand, eight hundred eight".