398968391 has 2 divisors, whose sum is σ = 398968392. Its totient is φ = 398968390.

The previous prime is 398968387. The next prime is 398968397. The reversal of 398968391 is 193869893.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 398968391 - 2² = 398968387 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398968397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199484195 + 199484196.

It is an arithmetic number, because the mean of its divisors is an integer number (199484196).

Almost surely, 2^398968391 is an apocalyptic number.

398968391 is a deficient number, since it is larger than the sum of its proper divisors (1).

398968391 is an equidigital number, since it uses as much as digits as its factorization.

398968391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2519424, while the sum is 56.

The square root of 398968391 is about 19974.1931251302. The cubic root of 398968391 is about 736.1723410757.

The spelling of 398968391 in words is "three hundred ninety-eight million, nine hundred sixty-eight thousand, three hundred ninety-one".