399216986 has 16 divisors (see below), whose sum is σ = 686168064. Its totient is φ = 170643984.

The previous prime is 399216913. The next prime is 399216989. The reversal of 399216986 is 689612993.

It is not an unprimeable number, because it can be changed into a prime (399216989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31865 + ... + 42588.

It is an arithmetic number, because the mean of its divisors is an integer number (42885504).

Almost surely, 2^399216986 is an apocalyptic number.

399216986 is a deficient number, since it is larger than the sum of its proper divisors (286951078).

399216986 is a wasteful number, since it uses less digits than its factorization.

399216986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74845.

The product of its digits is 1259712, while the sum is 53.

The square root of 399216986 is about 19980.4150607539. The cubic root of 399216986 is about 736.3252109687.

The spelling of 399216986 in words is "three hundred ninety-nine million, two hundred sixteen thousand, nine hundred eighty-six".