398331866 has 8 divisors (see below), whose sum is σ = 598572180. Its totient is φ = 198807808.

The previous prime is 398331859. The next prime is 398331877. The reversal of 398331866 is 668133893.

It can be written as a sum of positive squares in 2 ways, for example, as 287472025 + 110859841 = 16955^2 + 10529^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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 398331866.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177671 + ... + 179898.

Almost surely, 2^398331866 is an apocalyptic number.

398331866 is a deficient number, since it is larger than the sum of its proper divisors (200240314).

398331866 is a wasteful number, since it uses less digits than its factorization.

398331866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358128.

The product of its digits is 559872, while the sum is 47.

The square root of 398331866 is about 19958.2530798665. The cubic root of 398331866 is about 735.7806295746.

It can be divided in two parts, 3983 and 31866, that multiplied together give a triangular number (126922278 = T₁₅₉₃₂).

The spelling of 398331866 in words is "three hundred ninety-eight million, three hundred thirty-one thousand, eight hundred sixty-six".