398023817 has 2 divisors, whose sum is σ = 398023818. Its totient is φ = 398023816.

The previous prime is 398023789. The next prime is 398023831. The reversal of 398023817 is 718320893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 393784336 + 4239481 = 19844^2 + 2059^2 .

It is an emirp because it is prime and its reverse (718320893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 398023817 - 2¹⁸ = 397761673 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (398023877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199011908 + 199011909.

It is an arithmetic number, because the mean of its divisors is an integer number (199011909).

Almost surely, 2^398023817 is an apocalyptic number.

It is an amenable number.

398023817 is a deficient number, since it is larger than the sum of its proper divisors (1).

398023817 is an equidigital number, since it uses as much as digits as its factorization.

398023817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 398023817 is about 19950.5342534981. The cubic root of 398023817 is about 735.5909092604.

The spelling of 398023817 in words is "three hundred ninety-eight million, twenty-three thousand, eight hundred seventeen".