639942379615 has 16 divisors (see below), whose sum is σ = 957420288000. Its totient is φ = 398925119520.

The previous prime is 639942379607. The next prime is 639942379631. The reversal of 639942379615 is 516973249936.

It is not a de Polignac number, because 639942379615 - 2³ = 639942379607 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 831093615 + ... + 831094384.

It is an arithmetic number, because the mean of its divisors is an integer number (59838768000).

Almost surely, 2^639942379615 is an apocalyptic number.

639942379615 is a deficient number, since it is larger than the sum of its proper divisors (317477908385).

639942379615 is a wasteful number, since it uses less digits than its factorization.

639942379615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1662188022.

The product of its digits is 66134880, while the sum is 64.

The spelling of 639942379615 in words is "six hundred thirty-nine billion, nine hundred forty-two million, three hundred seventy-nine thousand, six hundred fifteen".