66665180 has 24 divisors (see below), whose sum is σ = 143413200. Its totient is φ = 26015360.

The previous prime is 66665161. The next prime is 66665189. The reversal of 66665180 is 8156666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66665189) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 39830 + ... + 41469.

It is an arithmetic number, because the mean of its divisors is an integer number (5975550).

Almost surely, 2^66665180 is an apocalyptic number.

It is an amenable number.

66665180 is an abundant number, since it is smaller than the sum of its proper divisors (76748020).

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

66665180 is a wasteful number, since it uses less digits than its factorization.

66665180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81349 (or 81347 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 66665180 is about 8164.8747694009. The cubic root of 66665180 is about 405.4771189468.

The spelling of 66665180 in words is "sixty-six million, six hundred sixty-five thousand, one hundred eighty".