399504816 has 30 divisors (see below), whose sum is σ = 1118059020. Its totient is φ = 133168224.

The previous prime is 399504757. The next prime is 399504821. The reversal of 399504816 is 618405993.

It is a happy number.

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 5 ways as a sum of consecutive naturals, for example, 1387026 + ... + 1387313.

It is an arithmetic number, because the mean of its divisors is an integer number (37268634).

Almost surely, 2^399504816 is an apocalyptic number.

399504816 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

399504816 is an abundant number, since it is smaller than the sum of its proper divisors (718554204).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399504816 is a wasteful number, since it uses less digits than its factorization.

399504816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2774353 (or 2774344 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The square root of 399504816 is about 19987.6165662642. The cubic root of 399504816 is about 736.5021286007.

The spelling of 399504816 in words is "three hundred ninety-nine million, five hundred four thousand, eight hundred sixteen".