638684486836 has 24 divisors (see below), whose sum is σ = 1272320086464. Its totient is φ = 277688906880.

The previous prime is 638684486809. The next prime is 638684486887.

638684486836 is nontrivially palindromic in base 10.

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, 315554565 + ... + 315556588.

It is an arithmetic number, because the mean of its divisors is an integer number (53013336936).

Almost surely, 2^638684486836 is an apocalyptic number.

It is an amenable number.

638684486836 is a deficient number, since it is larger than the sum of its proper divisors (633635599628).

638684486836 is a wasteful number, since it uses less digits than its factorization.

638684486836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 631111191 (or 631111189 counting only the distinct ones).

The product of its digits is 764411904, while the sum is 70.

The spelling of 638684486836 in words is "six hundred thirty-eight billion, six hundred eighty-four million, four hundred eighty-six thousand, eight hundred thirty-six".