398865 has 8 divisors (see below), whose sum is σ = 638208. Its totient is φ = 212720.

The previous prime is 398863. The next prime is 398887. The reversal of 398865 is 568893.

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

It is not a de Polignac number, because 398865 - 2¹ = 398863 is a prime.

It is a d-powerful number, because it can be written as 3 + 9 + 8⁴ + 8⁴ + 6² + 5⁸ .

It is not an unprimeable number, because it can be changed into a prime (398863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13281 + ... + 13310.

It is an arithmetic number, because the mean of its divisors is an integer number (79776).

2³⁹⁸⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

398865 is a deficient number, since it is larger than the sum of its proper divisors (239343).

398865 is a wasteful number, since it uses less digits than its factorization.

398865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26599.

The product of its digits is 51840, while the sum is 39.

The square root of 398865 is about 631.5575983234. The cubic root of 398865 is about 73.6108743581.

The spelling of 398865 in words is "three hundred ninety-eight thousand, eight hundred sixty-five".