398665 has 8 divisors (see below), whose sum is σ = 485568. Its totient is φ = 314160.

The previous prime is 398627. The next prime is 398669. The reversal of 398665 is 566893.

398665 is nontrivially palindromic in base 4.

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

It is not a de Polignac number, because 398665 - 2¹⁷ = 267593 is a prime.

It is a Duffinian number.

398665 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (398669) 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, 207 + ... + 916.

It is an arithmetic number, because the mean of its divisors is an integer number (60696).

2³⁹⁸⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

398665 is a deficient number, since it is larger than the sum of its proper divisors (86903).

398665 is a wasteful number, since it uses less digits than its factorization.

398665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1199.

The product of its digits is 38880, while the sum is 37.

The square root of 398665 is about 631.3992397841. The cubic root of 398665 is about 73.5985689112.

The spelling of 398665 in words is "three hundred ninety-eight thousand, six hundred sixty-five".