398428391 has 2 divisors, whose sum is σ = 398428392. Its totient is φ = 398428390.

The previous prime is 398428351. The next prime is 398428397. The reversal of 398428391 is 193824893.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-398428391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398428397) 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 as a sum of consecutive naturals, namely, 199214195 + 199214196.

It is an arithmetic number, because the mean of its divisors is an integer number (199214196).

Almost surely, 2^398428391 is an apocalyptic number.

398428391 is a deficient number, since it is larger than the sum of its proper divisors (1).

398428391 is an equidigital number, since it uses as much as digits as its factorization.

398428391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 47.

The square root of 398428391 is about 19960.6711059523. The cubic root of 398428391 is about 735.8400569812.

The spelling of 398428391 in words is "three hundred ninety-eight million, four hundred twenty-eight thousand, three hundred ninety-one".