816682566 has 64 divisors (see below), whose sum is σ = 1909831680. Its totient is φ = 228009600.

The previous prime is 816682561. The next prime is 816682639. The reversal of 816682566 is 665286618.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816682561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 333900 + ... + 336336.

It is an arithmetic number, because the mean of its divisors is an integer number (29841120).

Almost surely, 2^816682566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 816682566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (954915840).

816682566 is an abundant number, since it is smaller than the sum of its proper divisors (1093149114).

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

816682566 is a wasteful number, since it uses less digits than its factorization.

816682566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2629.

The product of its digits is 829440, while the sum is 48.

The square root of 816682566 is about 28577.6585115016. The cubic root of 816682566 is about 934.7262263834.

The spelling of 816682566 in words is "eight hundred sixteen million, six hundred eighty-two thousand, five hundred sixty-six".