66664685 has 8 divisors (see below), whose sum is σ = 80461080. Its totient is φ = 53022784.

The previous prime is 66664627. The next prime is 66664691. The reversal of 66664685 is 58646666.

It can be written as a sum of positive squares in 4 ways, for example, as 35450116 + 31214569 = 5954^2 + 5587^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66664685 - 2⁶ = 66664621 is a prime.

It is a super-2 number, since 2×66664685² = 8888360452298450, which contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 37670 + ... + 39399.

It is an arithmetic number, because the mean of its divisors is an integer number (10057635).

Almost surely, 2^66664685 is an apocalyptic number.

It is an amenable number.

66664685 is a deficient number, since it is larger than the sum of its proper divisors (13796395).

66664685 is a wasteful number, since it uses less digits than its factorization.

66664685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77247.

The product of its digits is 1244160, while the sum is 47.

The square root of 66664685 is about 8164.8444565711. The cubic root of 66664685 is about 405.4761153661.

The spelling of 66664685 in words is "sixty-six million, six hundred sixty-four thousand, six hundred eighty-five".