639788836635 has 48 divisors (see below), whose sum is σ = 1257128964000. Its totient is φ = 298395436032.

The previous prime is 639788836627. The next prime is 639788836657. The reversal of 639788836635 is 536638887936.

It is not a de Polignac number, because 639788836635 - 2³ = 639788836627 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 28769310 + ... + 28791539.

It is an arithmetic number, because the mean of its divisors is an integer number (26190186750).

Almost surely, 2^639788836635 is an apocalyptic number.

639788836635 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

639788836635 is a deficient number, since it is larger than the sum of its proper divisors (617340127365).

639788836635 is a wasteful number, since it uses less digits than its factorization.

639788836635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57560892 (or 57560889 counting only the distinct ones).

The product of its digits is 940584960, while the sum is 72.

The spelling of 639788836635 in words is "six hundred thirty-nine billion, seven hundred eighty-eight million, eight hundred thirty-six thousand, six hundred thirty-five".