398221 has 4 divisors (see below), whose sum is σ = 419200. Its totient is φ = 377244.

The previous prime is 398219. The next prime is 398227. The reversal of 398221 is 122893.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 122893 = 17 ⋅7229.

It is a cyclic number.

It is not a de Polignac number, because 398221 - 2¹ = 398219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10461 + ... + 10498.

It is an arithmetic number, because the mean of its divisors is an integer number (104800).

2³⁹⁸²²¹ is an apocalyptic number.

It is an amenable number.

398221 is a deficient number, since it is larger than the sum of its proper divisors (20979).

398221 is a wasteful number, since it uses less digits than its factorization.

398221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20978.

The product of its digits is 864, while the sum is 25.

The square root of 398221 is about 631.0475417906. The cubic root of 398221 is about 73.5712361018.

The spelling of 398221 in words is "three hundred ninety-eight thousand, two hundred twenty-one".