638403576838 has 16 divisors (see below), whose sum is σ = 962497055520. Its totient is φ = 317574383616.

The previous prime is 638403576817. The next prime is 638403576929. The reversal of 638403576838 is 838675304836.

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, 384645 + ... + 1193632.

It is an arithmetic number, because the mean of its divisors is an integer number (60156065970).

Almost surely, 2^638403576838 is an apocalyptic number.

638403576838 is a deficient number, since it is larger than the sum of its proper divisors (324093478682).

638403576838 is a wasteful number, since it uses less digits than its factorization.

638403576838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1579311.

The product of its (nonzero) digits is 69672960, while the sum is 61.

The spelling of 638403576838 in words is "six hundred thirty-eight billion, four hundred three million, five hundred seventy-six thousand, eight hundred thirty-eight".