66766580 has 12 divisors (see below), whose sum is σ = 140209860. Its totient is φ = 26706624.

The previous prime is 66766571. The next prime is 66766619. The reversal of 66766580 is 8566766.

It can be written as a sum of positive squares in 2 ways, for example, as 52823824 + 13942756 = 7268^2 + 3734^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1669145 + ... + 1669184.

It is an arithmetic number, because the mean of its divisors is an integer number (11684155).

Almost surely, 2^66766580 is an apocalyptic number.

It is an amenable number.

66766580 is an abundant number, since it is smaller than the sum of its proper divisors (73443280).

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

66766580 is a wasteful number, since it uses less digits than its factorization.

66766580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3338338 (or 3338336 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 44.

The square root of 66766580 is about 8171.0819357047. The cubic root of 66766580 is about 405.6825962865.

The spelling of 66766580 in words is "sixty-six million, seven hundred sixty-six thousand, five hundred eighty".