390805 has 8 divisors (see below), whose sum is σ = 479232. Its totient is φ = 305808.

The previous prime is 390791. The next prime is 390809. The reversal of 390805 is 508093.

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

It is a cyclic number.

It is not a de Polignac number, because 390805 - 2¹¹ = 388757 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 390805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390809) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 597 + ... + 1066.

It is an arithmetic number, because the mean of its divisors is an integer number (59904).

2³⁹⁰⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

390805 is a deficient number, since it is larger than the sum of its proper divisors (88427).

390805 is a wasteful number, since it uses less digits than its factorization.

390805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1715.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 390805 is about 625.1439834150. The cubic root of 390805 is about 73.1116699592. Note that the first 3 decimals are identical.

Adding to 390805 its reverse (508093), we get a palindrome (898898).

The spelling of 390805 in words is "three hundred ninety thousand, eight hundred five".