399365816 has 8 divisors (see below), whose sum is σ = 748810920. Its totient is φ = 199682904.

The previous prime is 399365803. The next prime is 399365833. The reversal of 399365816 is 618563993.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24960356 + ... + 24960371.

It is an arithmetic number, because the mean of its divisors is an integer number (93601365).

Almost surely, 2^399365816 is an apocalyptic number.

It is an amenable number.

399365816 is a deficient number, since it is larger than the sum of its proper divisors (349445104).

399365816 is a wasteful number, since it uses less digits than its factorization.

399365816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49920733 (or 49920729 counting only the distinct ones).

The product of its digits is 1049760, while the sum is 50.

The square root of 399365816 is about 19984.1391108048. The cubic root of 399365816 is about 736.4167014527.

The spelling of 399365816 in words is "three hundred ninety-nine million, three hundred sixty-five thousand, eight hundred sixteen".