638866668836 has 24 divisors (see below), whose sum is σ = 1227840163200. Its totient is φ = 288444984800.

The previous prime is 638866668763. The next prime is 638866668871.

It is a happy number.

638866668836 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48717260 + ... + 48730371.

It is an arithmetic number, because the mean of its divisors is an integer number (51160006800).

Almost surely, 2^638866668836 is an apocalyptic number.

It is an amenable number.

638866668836 is a deficient number, since it is larger than the sum of its proper divisors (588973494364).

638866668836 is a wasteful number, since it uses less digits than its factorization.

638866668836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97447795 (or 97447793 counting only the distinct ones).

The product of its digits is 1719926784, while the sum is 74.

The spelling of 638866668836 in words is "six hundred thirty-eight billion, eight hundred sixty-six million, six hundred sixty-eight thousand, eight hundred thirty-six".