66466639 has 4 divisors (see below), whose sum is σ = 66834040. Its totient is φ = 66099240.

The previous prime is 66466607. The next prime is 66466643. The reversal of 66466639 is 93666466.

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

It is a cyclic number.

It is not a de Polignac number, because 66466639 - 2⁵ = 66466607 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 (66466669) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 183429 + ... + 183790.

It is an arithmetic number, because the mean of its divisors is an integer number (16708510).

Almost surely, 2^66466639 is an apocalyptic number.

66466639 is a deficient number, since it is larger than the sum of its proper divisors (367401).

66466639 is a wasteful number, since it uses less digits than its factorization.

66466639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367400.

The product of its digits is 839808, while the sum is 46.

The square root of 66466639 is about 8152.7074643949. The cubic root of 66466639 is about 405.0741905440.

The spelling of 66466639 in words is "sixty-six million, four hundred sixty-six thousand, six hundred thirty-nine".