638927099938 has 16 divisors (see below), whose sum is σ = 1032293481120. Its totient is φ = 295611313536.

The previous prime is 638927099873. The next prime is 638927099939. The reversal of 638927099938 is 839990729836.

It is not an unprimeable number, because it can be changed into a prime (638927099939) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195508495 + ... + 195511762.

It is an arithmetic number, because the mean of its divisors is an integer number (64518342570).

Almost surely, 2^638927099938 is an apocalyptic number.

638927099938 is a deficient number, since it is larger than the sum of its proper divisors (393366381182).

638927099938 is a wasteful number, since it uses less digits than its factorization.

638927099938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391020321.

The product of its (nonzero) digits is 317447424, while the sum is 73.

The spelling of 638927099938 in words is "six hundred thirty-eight billion, nine hundred twenty-seven million, ninety-nine thousand, nine hundred thirty-eight".