394639879815 has 32 divisors (see below), whose sum is σ = 702753408000. Its totient is φ = 210123182880.

The previous prime is 394639879813. The next prime is 394639879819. The reversal of 394639879815 is 518978936493.

394639879815 is a `hidden beast` number, since 3 + 9 + 463 + 9 + 87 + 9 + 81 + 5 = 666.

It is not a de Polignac number, because 394639879815 - 2¹ = 394639879813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (394639879811) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 2359251 + ... + 2520980.

It is an arithmetic number, because the mean of its divisors is an integer number (21961044000).

Almost surely, 2^394639879815 is an apocalyptic number.

394639879815 is a deficient number, since it is larger than the sum of its proper divisors (308113528185).

394639879815 is a wasteful number, since it uses less digits than its factorization.

394639879815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4880844 (or 4880838 counting only the distinct ones).

The product of its digits is 352719360, while the sum is 72.

The spelling of 394639879815 in words is "three hundred ninety-four billion, six hundred thirty-nine million, eight hundred seventy-nine thousand, eight hundred fifteen".