391668401648 has 20 divisors (see below), whose sum is σ = 803496206880. Its totient is φ = 184314541824.

The previous prime is 391668401617. The next prime is 391668401669. The reversal of 391668401648 is 846104866193.

It is a junction number, because it is equal to n+sod(n) for n = 391668401593 and 391668401602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 719978408 + ... + 719978951.

It is an arithmetic number, because the mean of its divisors is an integer number (40174810344).

Almost surely, 2^391668401648 is an apocalyptic number.

It is an amenable number.

391668401648 is an abundant number, since it is smaller than the sum of its proper divisors (411827805232).

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

391668401648 is a wasteful number, since it uses less digits than its factorization.

391668401648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1439957384 (or 1439957378 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 56.

The spelling of 391668401648 in words is "three hundred ninety-one billion, six hundred sixty-eight million, four hundred one thousand, six hundred forty-eight".