390509 has 4 divisors (see below), whose sum is σ = 446304. Its totient is φ = 334716.

The previous prime is 390503. The next prime is 390527. The reversal of 390509 is 905093.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 390509 - 2⁴ = 390493 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 (390503) 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, 27887 + ... + 27900.

It is an arithmetic number, because the mean of its divisors is an integer number (111576).

2³⁹⁰⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

390509 is a deficient number, since it is larger than the sum of its proper divisors (55795).

390509 is an equidigital number, since it uses as much as digits as its factorization.

390509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55794.

The product of its (nonzero) digits is 1215, while the sum is 26.

The square root of 390509 is about 624.9071931095. The cubic root of 390509 is about 73.0932067697.

The spelling of 390509 in words is "three hundred ninety thousand, five hundred nine".