390243839 has 4 divisors (see below), whose sum is σ = 394945656. Its totient is φ = 385542024.

The previous prime is 390243811. The next prime is 390243851. The reversal of 390243839 is 938342093.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 938342093 = 13 ⋅72180161.

It is a cyclic number.

It is not a de Polignac number, because 390243839 - 2⁸ = 390243583 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 390243796 and 390243805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390243809) 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, 2350784 + ... + 2350949.

It is an arithmetic number, because the mean of its divisors is an integer number (98736414).

Almost surely, 2^390243839 is an apocalyptic number.

390243839 is a deficient number, since it is larger than the sum of its proper divisors (4701817).

390243839 is an equidigital number, since it uses as much as digits as its factorization.

390243839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4701816.

The product of its (nonzero) digits is 139968, while the sum is 41.

The square root of 390243839 is about 19754.5903273138. The cubic root of 390243839 is about 730.7665925846.

The spelling of 390243839 in words is "three hundred ninety million, two hundred forty-three thousand, eight hundred thirty-nine".