398818394 has 16 divisors (see below), whose sum is σ = 644663880. Its totient is φ = 183950400.

The previous prime is 398818391. The next prime is 398818447. The reversal of 398818394 is 493818893.

It can be written as a sum of positive squares in 4 ways, for example, as 51480625 + 347337769 = 7175^2 + 18637^2 .

It is a super-2 number, since 2×398818394² = 318112222785478472, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (398818391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45392 + ... + 53460.

Almost surely, 2^398818394 is an apocalyptic number.

398818394 is a deficient number, since it is larger than the sum of its proper divisors (245845486).

398818394 is a wasteful number, since it uses less digits than its factorization.

398818394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9985.

The product of its digits is 1492992, while the sum is 53.

The square root of 398818394 is about 19970.4380022072. The cubic root of 398818394 is about 736.0800718748.

The spelling of 398818394 in words is "three hundred ninety-eight million, eight hundred eighteen thousand, three hundred ninety-four".