398609 has 2 divisors, whose sum is σ = 398610. Its totient is φ = 398608.

The previous prime is 398591. The next prime is 398611. The reversal of 398609 is 906893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 394384 + 4225 = 628^2 + 65^2 .

It is a cyclic number.

It is not a de Polignac number, because 398609 - 2⁸ = 398353 is a prime.

Together with 398611, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (398669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199304 + 199305.

It is an arithmetic number, because the mean of its divisors is an integer number (199305).

2³⁹⁸⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

398609 is a deficient number, since it is larger than the sum of its proper divisors (1).

398609 is an equidigital number, since it uses as much as digits as its factorization.

398609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 398609 is about 631.3548922753. The cubic root of 398609 is about 73.5951226486.

The spelling of 398609 in words is "three hundred ninety-eight thousand, six hundred nine".