398407609 has 2 divisors, whose sum is σ = 398407610. Its totient is φ = 398407608.

The previous prime is 398407591. The next prime is 398407613. The reversal of 398407609 is 906704893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 394419600 + 3988009 = 19860^2 + 1997^2 .

It is a cyclic number.

It is not a de Polignac number, because 398407609 - 2¹⁵ = 398374841 is a prime.

It is not a weakly prime, because it can be changed into another prime (398417609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199203804 + 199203805.

It is an arithmetic number, because the mean of its divisors is an integer number (199203805).

Almost surely, 2^398407609 is an apocalyptic number.

It is an amenable number.

398407609 is a deficient number, since it is larger than the sum of its proper divisors (1).

398407609 is an equidigital number, since it uses as much as digits as its factorization.

398407609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 326592, while the sum is 46.

The square root of 398407609 is about 19960.1505254845. The cubic root of 398407609 is about 735.8272629683.

The spelling of 398407609 in words is "three hundred ninety-eight million, four hundred seven thousand, six hundred nine".