639117557905 has 16 divisors (see below), whose sum is σ = 814508625024. Its totient is φ = 479764074240.

The previous prime is 639117557887. The next prime is 639117557909. The reversal of 639117557905 is 509755711936.

It is not a de Polignac number, because 639117557905 - 2⁵ = 639117557873 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639117557905.

It is not an unprimeable number, because it can be changed into a prime (639117557909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11329917 + ... + 11386186.

It is an arithmetic number, because the mean of its divisors is an integer number (50906789064).

Almost surely, 2^639117557905 is an apocalyptic number.

It is an amenable number.

639117557905 is a deficient number, since it is larger than the sum of its proper divisors (175391067119).

639117557905 is a wasteful number, since it uses less digits than its factorization.

639117557905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22716456.

The product of its (nonzero) digits is 8930250, while the sum is 58.

The spelling of 639117557905 in words is "six hundred thirty-nine billion, one hundred seventeen million, five hundred fifty-seven thousand, nine hundred five".