816564799 has 8 divisors (see below), whose sum is σ = 838051920. Its totient is φ = 795302976.

The previous prime is 816564773. The next prime is 816564811. The reversal of 816564799 is 997465618.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-816564799 is a prime.

It is a super-3 number, since 3×816564799³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816564709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48969 + ... + 63490.

It is an arithmetic number, because the mean of its divisors is an integer number (104756490).

Almost surely, 2^816564799 is an apocalyptic number.

816564799 is a deficient number, since it is larger than the sum of its proper divisors (21487121).

816564799 is a wasteful number, since it uses less digits than its factorization.

816564799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112649.

The product of its digits is 3265920, while the sum is 55.

The square root of 816564799 is about 28575.5979639972. The cubic root of 816564799 is about 934.6812945255.

The spelling of 816564799 in words is "eight hundred sixteen million, five hundred sixty-four thousand, seven hundred ninety-nine".