638548970538 has 16 divisors (see below), whose sum is σ = 1277315168256. Its totient is φ = 212813452320.

The previous prime is 638548970473. The next prime is 638548970573. The reversal of 638548970538 is 835079845836.

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, 9012906 + ... + 9083477.

It is an arithmetic number, because the mean of its divisors is an integer number (79832198016).

Almost surely, 2^638548970538 is an apocalyptic number.

638548970538 is an abundant number, since it is smaller than the sum of its proper divisors (638766197718).

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

638548970538 is a wasteful number, since it uses less digits than its factorization.

638548970538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18102269.

The product of its (nonzero) digits is 174182400, while the sum is 66.

The spelling of 638548970538 in words is "six hundred thirty-eight billion, five hundred forty-eight million, nine hundred seventy thousand, five hundred thirty-eight".