398475409 has 2 divisors, whose sum is σ = 398475410. Its totient is φ = 398475408.

The previous prime is 398475397. The next prime is 398475443. The reversal of 398475409 is 904574893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 390181009 + 8294400 = 19753^2 + 2880^2 .

It is an emirp because it is prime and its reverse (904574893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 398475409 - 2¹⁹ = 397951121 is a prime.

It is not a weakly prime, because it can be changed into another prime (398475449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199237704 + 199237705.

It is an arithmetic number, because the mean of its divisors is an integer number (199237705).

Almost surely, 2^398475409 is an apocalyptic number.

It is an amenable number.

398475409 is a deficient number, since it is larger than the sum of its proper divisors (1).

398475409 is an equidigital number, since it uses as much as digits as its factorization.

398475409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1088640, while the sum is 49.

The square root of 398475409 is about 19961.8488372195. The cubic root of 398475409 is about 735.8690010088.

The spelling of 398475409 in words is "three hundred ninety-eight million, four hundred seventy-five thousand, four hundred nine".