816564801 has 8 divisors (see below), whose sum is σ = 1172503360. Its totient is φ = 502501392.

The previous prime is 816564773. The next prime is 816564811. The reversal of 816564801 is 108465618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 816564801 - 2⁶ = 816564737 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 20937559 = 816564801 / (8 + 1 + 6 + 5 + 6 + 4 + 8 + 0 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 816564801.

It is not an unprimeable number, because it can be changed into a prime (816564811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10468741 + ... + 10468818.

It is an arithmetic number, because the mean of its divisors is an integer number (146562920).

Almost surely, 2^816564801 is an apocalyptic number.

It is an amenable number.

816564801 is a deficient number, since it is larger than the sum of its proper divisors (355938559).

816564801 is a wasteful number, since it uses less digits than its factorization.

816564801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20937575.

The product of its (nonzero) digits is 46080, while the sum is 39.

The square root of 816564801 is about 28575.5979989921. The cubic root of 816564801 is about 934.6812952886.

The spelling of 816564801 in words is "eight hundred sixteen million, five hundred sixty-four thousand, eight hundred one".