6391979916438 has 96 divisors (see below), whose sum is σ = 14416944109920. Its totient is φ = 1882353116160.

The previous prime is 6391979916401. The next prime is 6391979916449. The reversal of 6391979916438 is 8346199791936.

It is a self number, because there is not a number n which added to its sum of digits gives 6391979916438.

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 47 ways as a sum of consecutive naturals, for example, 3217308 + ... + 4809888.

It is an arithmetic number, because the mean of its divisors is an integer number (150176501145).

Almost surely, 2^{6391979916438} is an apocalyptic number.

6391979916438 is an abundant number, since it is smaller than the sum of its proper divisors (8024964193482).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6391979916438 is a wasteful number, since it uses less digits than its factorization.

6391979916438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1592750 (or 1592731 counting only the distinct ones).

The product of its digits is 476171136, while the sum is 75.

The spelling of 6391979916438 in words is "six trillion, three hundred ninety-one billion, nine hundred seventy-nine million, nine hundred sixteen thousand, four hundred thirty-eight".