66666330625 has 10 divisors (see below), whose sum is σ = 83306247530. Its totient is φ = 53333064000.

The previous prime is 66666330593. The next prime is 66666330629. The reversal of 66666330625 is 52603366666.

It is a happy number.

It can be written as a sum of positive squares in 5 ways, for example, as 45487931841 + 21178398784 = 213279^2 + 145528^2 .

It is not a de Polignac number, because 66666330625 - 2⁵ = 66666330593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66666330629) 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 9 ways as a sum of consecutive naturals, for example, 53332440 + ... + 53333689.

It is an arithmetic number, because the mean of its divisors is an integer number (8330624753).

Almost surely, 2^66666330625 is an apocalyptic number.

It is an amenable number.

66666330625 is a deficient number, since it is larger than the sum of its proper divisors (16639916905).

66666330625 is an equidigital number, since it uses as much as digits as its factorization.

66666330625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106666149 (or 106666134 counting only the distinct ones).

The product of its (nonzero) digits is 4199040, while the sum is 49.

The spelling of 66666330625 in words is "sixty-six billion, six hundred sixty-six million, three hundred thirty thousand, six hundred twenty-five".