398391 has 16 divisors (see below), whose sum is σ = 619008. Its totient is φ = 223200.

The previous prime is 398369. The next prime is 398393. The reversal of 398391 is 193893.

It is not a de Polignac number, because 398391 - 2¹³ = 390199 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1126 + ... + 1436.

It is an arithmetic number, because the mean of its divisors is an integer number (38688).

2³⁹⁸³⁹¹ is an apocalyptic number.

398391 is a deficient number, since it is larger than the sum of its proper divisors (220617).

398391 is a wasteful number, since it uses less digits than its factorization.

398391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382.

The product of its digits is 5832, while the sum is 33.

The square root of 398391 is about 631.1822240843. The cubic root of 398391 is about 73.5817037658.

The spelling of 398391 in words is "three hundred ninety-eight thousand, three hundred ninety-one".