66664825 has 24 divisors (see below), whose sum is σ = 87494400. Its totient is φ = 50247360.

The previous prime is 66664813. The next prime is 66664859. The reversal of 66664825 is 52846666.

It is not a de Polignac number, because 66664825 - 2¹¹ = 66662777 is a prime.

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 23 ways as a sum of consecutive naturals, for example, 138936 + ... + 139414.

It is an arithmetic number, because the mean of its divisors is an integer number (3645600).

Almost surely, 2^66664825 is an apocalyptic number.

It is an amenable number.

66664825 is a deficient number, since it is larger than the sum of its proper divisors (20829575).

66664825 is a wasteful number, since it uses less digits than its factorization.

66664825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801 (or 796 counting only the distinct ones).

The product of its digits is 414720, while the sum is 43.

The square root of 66664825 is about 8164.8530299081. The cubic root of 66664825 is about 405.4763992076.

The spelling of 66664825 in words is "sixty-six million, six hundred sixty-four thousand, eight hundred twenty-five".