398180609 has 2 divisors, whose sum is σ = 398180610. Its totient is φ = 398180608.

The previous prime is 398180551. The next prime is 398180639. The reversal of 398180609 is 906081893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 372374209 + 25806400 = 19297^2 + 5080^2 .

It is a cyclic number.

It is not a de Polignac number, because 398180609 - 2²⁰ = 397132033 is a prime.

It is a super-2 number, since 2×398180609² = 317095594767221762, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 398180609.

It is not a weakly prime, because it can be changed into another prime (398180639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199090304 + 199090305.

It is an arithmetic number, because the mean of its divisors is an integer number (199090305).

Almost surely, 2^398180609 is an apocalyptic number.

It is an amenable number.

398180609 is a deficient number, since it is larger than the sum of its proper divisors (1).

398180609 is an equidigital number, since it uses as much as digits as its factorization.

398180609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 398180609 is about 19954.4633854183. The cubic root of 398180609 is about 735.6874860846.

The spelling of 398180609 in words is "three hundred ninety-eight million, one hundred eighty thousand, six hundred nine".