391397423 has 4 divisors (see below), whose sum is σ = 392648208. Its totient is φ = 390146640.

The previous prime is 391397401. The next prime is 391397429. The reversal of 391397423 is 324793193.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 324793193 = 83 ⋅3913171.

It is a cyclic number.

It is not a de Polignac number, because 391397423 - 2¹⁸ = 391135279 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 (391397429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 624923 + ... + 625548.

It is an arithmetic number, because the mean of its divisors is an integer number (98162052).

Almost surely, 2^391397423 is an apocalyptic number.

391397423 is a deficient number, since it is larger than the sum of its proper divisors (1250785).

391397423 is a wasteful number, since it uses less digits than its factorization.

391397423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1250784.

The product of its digits is 122472, while the sum is 41.

The square root of 391397423 is about 19783.7666534965. The cubic root of 391397423 is about 731.4859474023.

The spelling of 391397423 in words is "three hundred ninety-one million, three hundred ninety-seven thousand, four hundred twenty-three".