398565 has 24 divisors (see below), whose sum is σ = 732888. Its totient is φ = 199680.

The previous prime is 398557. The next prime is 398569. The reversal of 398565 is 565893.

398565 is a `hidden beast` number, since 3 + 98 + 565 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 49284 + 349281 = 222^2 + 591^2 .

It is not a de Polignac number, because 398565 - 2³ = 398557 is a prime.

It is a Curzon number.

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398569) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 505 + ... + 1025.

It is an arithmetic number, because the mean of its divisors is an integer number (30537).

2³⁹⁸⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

398565 is a deficient number, since it is larger than the sum of its proper divisors (334323).

398565 is a wasteful number, since it uses less digits than its factorization.

398565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 549 (or 546 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 398565 is about 631.3200456187. The cubic root of 398565 is about 73.5924146444.

The spelling of 398565 in words is "three hundred ninety-eight thousand, five hundred sixty-five".