398378666 has 32 divisors (see below), whose sum is σ = 695495808. Its totient is φ = 167616000.

The previous prime is 398378623. The next prime is 398378689. The reversal of 398378666 is 666873893.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 255746 + ... + 257298.

It is an arithmetic number, because the mean of its divisors is an integer number (21734244).

Almost surely, 2^398378666 is an apocalyptic number.

398378666 is a deficient number, since it is larger than the sum of its proper divisors (297117142).

398378666 is a wasteful number, since it uses less digits than its factorization.

398378666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1886.

The product of its digits is 7838208, while the sum is 56.

The square root of 398378666 is about 19959.4254927340. The cubic root of 398378666 is about 735.8094440615.

The spelling of 398378666 in words is "three hundred ninety-eight million, three hundred seventy-eight thousand, six hundred sixty-six".