398165666 has 16 divisors (see below), whose sum is σ = 609330048. Its totient is φ = 195080400.

The previous prime is 398165641. The next prime is 398165671. The reversal of 398165666 is 666561893.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27041 + ... + 39083.

It is an arithmetic number, because the mean of its divisors is an integer number (38083128).

Almost surely, 2^398165666 is an apocalyptic number.

398165666 is a deficient number, since it is larger than the sum of its proper divisors (211164382).

398165666 is a wasteful number, since it uses less digits than its factorization.

398165666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12377.

The product of its digits is 1399680, while the sum is 50.

The square root of 398165666 is about 19954.0889543973. The cubic root of 398165666 is about 735.6782829614.

The spelling of 398165666 in words is "three hundred ninety-eight million, one hundred sixty-five thousand, six hundred sixty-six".