390243 has 8 divisors (see below), whose sum is σ = 594688. Its totient is φ = 222984.

The previous prime is 390223. The next prime is 390263. The reversal of 390243 is 342093.

It is an interprime number because it is at equal distance from previous prime (390223) and next prime (390263).

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

It is not a de Polignac number, because 390243 - 2⁵ = 390211 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 18583 = 390243 / (3 + 9 + 0 + 2 + 4 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (390223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9271 + ... + 9312.

It is an arithmetic number, because the mean of its divisors is an integer number (74336).

2³⁹⁰²⁴³ is an apocalyptic number.

390243 is a deficient number, since it is larger than the sum of its proper divisors (204445).

390243 is a wasteful number, since it uses less digits than its factorization.

390243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18593.

The product of its (nonzero) digits is 648, while the sum is 21.

The square root of 390243 is about 624.6943252504. The cubic root of 390243 is about 73.0766068883.

The spelling of 390243 in words is "three hundred ninety thousand, two hundred forty-three".