391238347823 has 4 divisors (see below), whose sum is σ = 391239740088. Its totient is φ = 391236955560.

The previous prime is 391238347793. The next prime is 391238347831. The reversal of 391238347823 is 328743832193.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 391238347823 - 2¹⁰ = 391238346799 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 (391238347523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110261 + ... + 891422.

It is an arithmetic number, because the mean of its divisors is an integer number (97809935022).

Almost surely, 2^391238347823 is an apocalyptic number.

391238347823 is a deficient number, since it is larger than the sum of its proper divisors (1392265).

391238347823 is a wasteful number, since it uses less digits than its factorization.

391238347823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1392264.

The product of its digits is 5225472, while the sum is 53.

The spelling of 391238347823 in words is "three hundred ninety-one billion, two hundred thirty-eight million, three hundred forty-seven thousand, eight hundred twenty-three".