66606464720 has 60 divisors (see below), whose sum is σ = 158729548620. Its totient is φ = 25992714240.

The previous prime is 66606464719. The next prime is 66606464723. The reversal of 66606464720 is 2746460666.

It can be written as a sum of positive squares in 6 ways, for example, as 29966379664 + 36640085056 = 173108^2 + 191416^2 .

It is a super-2 number, since 2×66606464720² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66606464723) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 113165 + ... + 382124.

It is an arithmetic number, because the mean of its divisors is an integer number (2645492477).

Almost surely, 2^66606464720 is an apocalyptic number.

It is an amenable number.

66606464720 is an abundant number, since it is smaller than the sum of its proper divisors (92123083900).

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

66606464720 is a wasteful number, since it uses less digits than its factorization.

66606464720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495384 (or 495337 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 47.

The spelling of 66606464720 in words is "sixty-six billion, six hundred six million, four hundred sixty-four thousand, seven hundred twenty".