398396191 has 4 divisors (see below), whose sum is σ = 398645712. Its totient is φ = 398146672.

The previous prime is 398396189. The next prime is 398396213. The reversal of 398396191 is 191693893.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 398396191 - 2¹ = 398396189 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 (398396891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122350 + ... + 125563.

It is an arithmetic number, because the mean of its divisors is an integer number (99661428).

Almost surely, 2^398396191 is an apocalyptic number.

398396191 is a deficient number, since it is larger than the sum of its proper divisors (249521).

398396191 is a wasteful number, since it uses less digits than its factorization.

398396191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249520.

The product of its digits is 314928, while the sum is 49.

The square root of 398396191 is about 19959.8645035481. The cubic root of 398396191 is about 735.8202335210.

The spelling of 398396191 in words is "three hundred ninety-eight million, three hundred ninety-six thousand, one hundred ninety-one".