398193391 has 2 divisors, whose sum is σ = 398193392. Its totient is φ = 398193390.

The previous prime is 398193379. The next prime is 398193449. The reversal of 398193391 is 193391893.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-398193391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398193491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199096695 + 199096696.

It is an arithmetic number, because the mean of its divisors is an integer number (199096696).

Almost surely, 2^398193391 is an apocalyptic number.

398193391 is a deficient number, since it is larger than the sum of its proper divisors (1).

398193391 is an equidigital number, since it uses as much as digits as its factorization.

398193391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157464, while the sum is 46.

The square root of 398193391 is about 19954.7836620696. The cubic root of 398193391 is about 735.6953581044.

The spelling of 398193391 in words is "three hundred ninety-eight million, one hundred ninety-three thousand, three hundred ninety-one".