66645575 has 6 divisors (see below), whose sum is σ = 82640544. Its totient is φ = 53316440.

The previous prime is 66645517. The next prime is 66645583. The reversal of 66645575 is 57554666.

It is not a de Polignac number, because 66645575 - 2¹⁰ = 66644551 is a prime.

It is a Duffinian number.

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 5 ways as a sum of consecutive naturals, for example, 1332887 + ... + 1332936.

It is an arithmetic number, because the mean of its divisors is an integer number (13773424).

Almost surely, 2^66645575 is an apocalyptic number.

66645575 is a deficient number, since it is larger than the sum of its proper divisors (15994969).

66645575 is a wasteful number, since it uses less digits than its factorization.

66645575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2665833 (or 2665828 counting only the distinct ones).

The product of its digits is 756000, while the sum is 44.

The square root of 66645575 is about 8163.6741115750. The cubic root of 66645575 is about 405.4373672689.

Subtracting from 66645575 its reverse (57554666), we obtain a palindrome (9090909).

The spelling of 66645575 in words is "sixty-six million, six hundred forty-five thousand, five hundred seventy-five".