816728289 has 16 divisors (see below), whose sum is σ = 1179941952. Its totient is φ = 499514688.

The previous prime is 816728273. The next prime is 816728293. The reversal of 816728289 is 982827618.

It is a happy number.

It is not a de Polignac number, because 816728289 - 2⁴ = 816728273 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (816728219) 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 15 ways as a sum of consecutive naturals, for example, 57882 + ... + 70595.

It is an arithmetic number, because the mean of its divisors is an integer number (73746372).

Almost surely, 2^816728289 is an apocalyptic number.

It is an amenable number.

816728289 is a deficient number, since it is larger than the sum of its proper divisors (363213663).

816728289 is a wasteful number, since it uses less digits than its factorization.

816728289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128656.

The product of its digits is 774144, while the sum is 51.

The square root of 816728289 is about 28578.4584783714. The cubic root of 816728289 is about 934.7436699988.

The spelling of 816728289 in words is "eight hundred sixteen million, seven hundred twenty-eight thousand, two hundred eighty-nine".