398428091 has 2 divisors, whose sum is σ = 398428092. Its totient is φ = 398428090.

The previous prime is 398428061. The next prime is 398428111. The reversal of 398428091 is 190824893.

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-398428091 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (398428021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199214045 + 199214046.

It is an arithmetic number, because the mean of its divisors is an integer number (199214046).

Almost surely, 2^398428091 is an apocalyptic number.

398428091 is a deficient number, since it is larger than the sum of its proper divisors (1).

398428091 is an equidigital number, since it uses as much as digits as its factorization.

398428091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 398428091 is about 19960.6635911735. The cubic root of 398428091 is about 735.8398722956.

The spelling of 398428091 in words is "three hundred ninety-eight million, four hundred twenty-eight thousand, ninety-one".