66566766 has 32 divisors (see below), whose sum is σ = 160162560. Its totient is φ = 18017856.

The previous prime is 66566723. The next prime is 66566779. The reversal of 66566766 is 66766566.

It is a super-2 number, since 2×66566766² = 8862268671397512, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40911 + ... + 42506.

It is an arithmetic number, because the mean of its divisors is an integer number (5005080).

Almost surely, 2^66566766 is an apocalyptic number.

66566766 is an abundant number, since it is smaller than the sum of its proper divisors (93595794).

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

66566766 is a wasteful number, since it uses less digits than its factorization.

66566766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83448.

The product of its digits is 1632960, while the sum is 48.

The square root of 66566766 is about 8158.8458742643. The cubic root of 66566766 is about 405.2774931071.

The spelling of 66566766 in words is "sixty-six million, five hundred sixty-six thousand, seven hundred sixty-six".