398618985 has 32 divisors (see below), whose sum is σ = 658782720. Its totient is φ = 205703168.

The previous prime is 398618929. The next prime is 398618999. The reversal of 398618985 is 589816893.

It is a cyclic number.

It is not a de Polignac number, because 398618985 - 2¹⁴ = 398602601 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59569 + ... + 65921.

It is an arithmetic number, because the mean of its divisors is an integer number (20586960).

Almost surely, 2^398618985 is an apocalyptic number.

It is an amenable number.

398618985 is a deficient number, since it is larger than the sum of its proper divisors (260163735).

398618985 is a wasteful number, since it uses less digits than its factorization.

398618985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6497.

The product of its digits is 3732480, while the sum is 57.

The square root of 398618985 is about 19965.4447734079. Note that the first 3 decimals coincide. The cubic root of 398618985 is about 735.9573715317.

The spelling of 398618985 in words is "three hundred ninety-eight million, six hundred eighteen thousand, nine hundred eighty-five".