638636685304 has 16 divisors (see below), whose sum is σ = 1209069454320. Its totient is φ = 316218164160.

The previous prime is 638636685301. The next prime is 638636685311. The reversal of 638636685304 is 403586636836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638636685301) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 387521437 + ... + 387523084.

It is an arithmetic number, because the mean of its divisors is an integer number (75566840895).

Almost surely, 2^638636685304 is an apocalyptic number.

It is an amenable number.

638636685304 is a deficient number, since it is larger than the sum of its proper divisors (570432769016).

638636685304 is a wasteful number, since it uses less digits than its factorization.

638636685304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 775044630 (or 775044626 counting only the distinct ones).

The product of its (nonzero) digits is 44789760, while the sum is 58.

The spelling of 638636685304 in words is "six hundred thirty-eight billion, six hundred thirty-six million, six hundred eighty-five thousand, three hundred four".