391779964889823 has 8 divisors (see below), whose sum is σ = 530936783020336. Its totient is φ = 256904895009600.

The previous prime is 391779964889821. The next prime is 391779964889921. The reversal of 391779964889823 is 328988469977193.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 391779964889823 - 2¹ = 391779964889821 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 (391779964889821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1070437062358 + ... + 1070437062723.

It is an arithmetic number, because the mean of its divisors is an integer number (66367097877542).

Almost surely, 2^{391779964889823} is an apocalyptic number.

391779964889823 is a deficient number, since it is larger than the sum of its proper divisors (139156818130513).

391779964889823 is a wasteful number, since it uses less digits than its factorization.

391779964889823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2140874125145.

The product of its digits is 71108222976, while the sum is 93.

The spelling of 391779964889823 in words is "three hundred ninety-one trillion, seven hundred seventy-nine billion, nine hundred sixty-four million, eight hundred eighty-nine thousand, eight hundred twenty-three".