390815 has 4 divisors (see below), whose sum is σ = 468984. Its totient is φ = 312648.

The previous prime is 390809. The next prime is 390821. The reversal of 390815 is 518093.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 518093 = 379 ⋅1367.

It is an interprime number because it is at equal distance from previous prime (390809) and next prime (390821).

It is a cyclic number.

It is not a de Polignac number, because 390815 - 2⁶ = 390751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39077 + ... + 39086.

It is an arithmetic number, because the mean of its divisors is an integer number (117246).

2³⁹⁰⁸¹⁵ is an apocalyptic number.

390815 is a deficient number, since it is larger than the sum of its proper divisors (78169).

390815 is an equidigital number, since it uses as much as digits as its factorization.

390815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78168.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 390815 is about 625.1519815213. The cubic root of 390815 is about 73.1122935528.

The spelling of 390815 in words is "three hundred ninety thousand, eight hundred fifteen".