816612666 has 16 divisors (see below), whose sum is σ = 1719184800. Its totient is φ = 257877648.

The previous prime is 816612661. The next prime is 816612679. The reversal of 816612666 is 666216618.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (816612661) 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, 3581521 + ... + 3581748.

It is an arithmetic number, because the mean of its divisors is an integer number (107449050).

Almost surely, 2^816612666 is an apocalyptic number.

816612666 is an abundant number, since it is smaller than the sum of its proper divisors (902572134).

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

816612666 is a wasteful number, since it uses less digits than its factorization.

816612666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7163293.

The product of its digits is 124416, while the sum is 42.

The square root of 816612666 is about 28576.4355020006. The cubic root of 816612666 is about 934.6995578302.

The spelling of 816612666 in words is "eight hundred sixteen million, six hundred twelve thousand, six hundred sixty-six".