66607188565 has 4 divisors (see below), whose sum is σ = 79928626284. Its totient is φ = 53285750848.

The previous prime is 66607188563. The next prime is 66607188601. The reversal of 66607188565 is 56588170666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 36511184241 + 30096004324 = 191079^2 + 173482^2 .

It is a cyclic number.

It is not a de Polignac number, because 66607188565 - 2¹ = 66607188563 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66607188563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6660718852 + ... + 6660718861.

It is an arithmetic number, because the mean of its divisors is an integer number (19982156571).

Almost surely, 2^66607188565 is an apocalyptic number.

It is an amenable number.

66607188565 is a deficient number, since it is larger than the sum of its proper divisors (13321437719).

66607188565 is a wasteful number, since it uses less digits than its factorization.

66607188565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13321437718.

The product of its (nonzero) digits is 14515200, while the sum is 58.

The spelling of 66607188565 in words is "sixty-six billion, six hundred seven million, one hundred eighty-eight thousand, five hundred sixty-five".