398609923 has 2 divisors, whose sum is σ = 398609924. Its totient is φ = 398609922.

The previous prime is 398609921. The next prime is 398609963. The reversal of 398609923 is 329906893.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (329906893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 398609923 - 2¹ = 398609921 is a prime.

Together with 398609921, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (398609921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199304961 + 199304962.

It is an arithmetic number, because the mean of its divisors is an integer number (199304962).

Almost surely, 2^398609923 is an apocalyptic number.

398609923 is a deficient number, since it is larger than the sum of its proper divisors (1).

398609923 is an equidigital number, since it uses as much as digits as its factorization.

398609923 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 629856, while the sum is 49.

The square root of 398609923 is about 19965.2178300163. The cubic root of 398609923 is about 735.9517945300.

The spelling of 398609923 in words is "three hundred ninety-eight million, six hundred nine thousand, nine hundred twenty-three".