639381599999 has 4 divisors (see below), whose sum is σ = 639483792864. Its totient is φ = 639279407136.

The previous prime is 639381599959. The next prime is 639381600007. The reversal of 639381599999 is 999995183936.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 639381599999 - 2⁸ = 639381599743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639381599959) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51087047 + ... + 51099560.

It is an arithmetic number, because the mean of its divisors is an integer number (159870948216).

Almost surely, 2^639381599999 is an apocalyptic number.

639381599999 is a deficient number, since it is larger than the sum of its proper divisors (102192865).

639381599999 is a wasteful number, since it uses less digits than its factorization.

639381599999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102192864.

The product of its digits is 1147912560, while the sum is 80.

The spelling of 639381599999 in words is "six hundred thirty-nine billion, three hundred eighty-one million, five hundred ninety-nine thousand, nine hundred ninety-nine".