638613620648 has 32 divisors (see below), whose sum is σ = 1281784716000. Its totient is φ = 297374045760.

The previous prime is 638613620633. The next prime is 638613620677. The reversal of 638613620648 is 846026316836.

It is a self number, because there is not a number n which added to its sum of digits gives 638613620648.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35596163 + ... + 35614098.

It is an arithmetic number, because the mean of its divisors is an integer number (40055772375).

Almost surely, 2^638613620648 is an apocalyptic number.

It is an amenable number.

638613620648 is an abundant number, since it is smaller than the sum of its proper divisors (643171095352).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638613620648 is a wasteful number, since it uses less digits than its factorization.

638613620648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71210345 (or 71210341 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 53.

The spelling of 638613620648 in words is "six hundred thirty-eight billion, six hundred thirteen million, six hundred twenty thousand, six hundred forty-eight".