393691816 has 64 divisors (see below), whose sum is σ = 875381760. Its totient is φ = 162432000.

The previous prime is 393691813. The next prime is 393691817. The reversal of 393691816 is 618196393.

It is not an unprimeable number, because it can be changed into a prime (393691813) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 417906 + ... + 418846.

It is an arithmetic number, because the mean of its divisors is an integer number (13677840).

Almost surely, 2^393691816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 393691816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (437690880).

393691816 is an abundant number, since it is smaller than the sum of its proper divisors (481689944).

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

393691816 is a wasteful number, since it uses less digits than its factorization.

393691816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1226 (or 1222 counting only the distinct ones).

The product of its digits is 209952, while the sum is 46.

The square root of 393691816 is about 19841.6686798263. The cubic root of 393691816 is about 732.9125003271.

The spelling of 393691816 in words is "three hundred ninety-three million, six hundred ninety-one thousand, eight hundred sixteen".