390505 has 4 divisors (see below), whose sum is σ = 468612. Its totient is φ = 312400.

The previous prime is 390503. The next prime is 390527. The reversal of 390505 is 505093.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 505093 = 29 ⋅17417.

It can be written as a sum of positive squares in 2 ways, for example, as 243049 + 147456 = 493^2 + 384^2 .

It is not a de Polignac number, because 390505 - 2¹ = 390503 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (390503) 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, 39046 + ... + 39055.

It is an arithmetic number, because the mean of its divisors is an integer number (117153).

2³⁹⁰⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

390505 is a deficient number, since it is larger than the sum of its proper divisors (78107).

390505 is an equidigital number, since it uses as much as digits as its factorization.

390505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78106.

The product of its (nonzero) digits is 675, while the sum is 22.

The square root of 390505 is about 624.9039926261. The cubic root of 390505 is about 73.0929572033.

Adding to 390505 its reverse (505093), we get a palindrome (895598).

The spelling of 390505 in words is "three hundred ninety thousand, five hundred five".