816688633 has 4 divisors (see below), whose sum is σ = 844850340. Its totient is φ = 788526928.

The previous prime is 816688627. The next prime is 816688651. The reversal of 816688633 is 336886618.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 406909584 + 409779049 = 20172^2 + 20243^2 .

It is a cyclic number.

It is not a de Polignac number, because 816688633 - 2¹⁷ = 816557561 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816688603) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14080810 + ... + 14080867.

It is an arithmetic number, because the mean of its divisors is an integer number (211212585).

Almost surely, 2^816688633 is an apocalyptic number.

It is an amenable number.

816688633 is a deficient number, since it is larger than the sum of its proper divisors (28161707).

816688633 is a wasteful number, since it uses less digits than its factorization.

816688633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28161706.

The product of its digits is 995328, while the sum is 49.

The square root of 816688633 is about 28577.7646606588. The cubic root of 816688633 is about 934.7285410200.

The spelling of 816688633 in words is "eight hundred sixteen million, six hundred eighty-eight thousand, six hundred thirty-three".