638958939843 has 32 divisors (see below), whose sum is σ = 974695002112. Its totient is φ = 364728420000.

The previous prime is 638958939821. The next prime is 638958939863. The reversal of 638958939843 is 348939859836.

It is not a de Polignac number, because 638958939843 - 2⁵ = 638958939811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638958939863) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 100731330 + ... + 100737672.

It is an arithmetic number, because the mean of its divisors is an integer number (30459218816).

Almost surely, 2^638958939843 is an apocalyptic number.

638958939843 is a deficient number, since it is larger than the sum of its proper divisors (335736062269).

638958939843 is a wasteful number, since it uses less digits than its factorization.

638958939843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10735.

The product of its digits is 1209323520, while the sum is 75.

The spelling of 638958939843 in words is "six hundred thirty-eight billion, nine hundred fifty-eight million, nine hundred thirty-nine thousand, eight hundred forty-three".