66666659 has 8 divisors (see below), whose sum is σ = 67223520. Its totient is φ = 66112576.

The previous prime is 66666653. The next prime is 66666667. The reversal of 66666659 is 95666666.

66666659 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 66666659 - 2⁴ = 66666643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66666653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83249 + ... + 84045.

It is an arithmetic number, because the mean of its divisors is an integer number (8402940).

Almost surely, 2^66666659 is an apocalyptic number.

66666659 is a deficient number, since it is larger than the sum of its proper divisors (556861).

66666659 is a wasteful number, since it uses less digits than its factorization.

66666659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1389.

The product of its digits is 2099520, while the sum is 50.

The square root of 66666659 is about 8164.9653397917. The cubic root of 66666659 is about 405.4801174948.

The spelling of 66666659 in words is "sixty-six million, six hundred sixty-six thousand, six hundred fifty-nine".