398249009 has 2 divisors, whose sum is σ = 398249010. Its totient is φ = 398249008.

The previous prime is 398248973. The next prime is 398249017. The reversal of 398249009 is 900942893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 390931984 + 7317025 = 19772^2 + 2705^2 .

It is a cyclic number.

It is not a de Polignac number, because 398249009 - 2¹⁶ = 398183473 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (398249029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199124504 + 199124505.

It is an arithmetic number, because the mean of its divisors is an integer number (199124505).

Almost surely, 2^398249009 is an apocalyptic number.

It is an amenable number.

398249009 is a deficient number, since it is larger than the sum of its proper divisors (1).

398249009 is an equidigital number, since it uses as much as digits as its factorization.

398249009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 398249009 is about 19956.1772140859. The cubic root of 398249009 is about 735.7296094677.

The spelling of 398249009 in words is "three hundred ninety-eight million, two hundred forty-nine thousand, nine".