398165 has 4 divisors (see below), whose sum is σ = 477804. Its totient is φ = 318528.

The previous prime is 398149. The next prime is 398171. The reversal of 398165 is 561893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 561893 = 211 ⋅2663.

It can be written as a sum of positive squares in 2 ways, for example, as 142129 + 256036 = 377^2 + 506^2 .

It is a cyclic number.

It is not a de Polignac number, because 398165 - 2⁴ = 398149 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, 39812 + ... + 39821.

It is an arithmetic number, because the mean of its divisors is an integer number (119451).

2³⁹⁸¹⁶⁵ is an apocalyptic number.

It is an amenable number.

398165 is a deficient number, since it is larger than the sum of its proper divisors (79639).

398165 is an equidigital number, since it uses as much as digits as its factorization.

398165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79638.

The product of its digits is 6480, while the sum is 32.

The square root of 398165 is about 631.0031695641. The cubic root of 398165 is about 73.5677872779.

The spelling of 398165 in words is "three hundred ninety-eight thousand, one hundred sixty-five".