66669664 has 12 divisors (see below), whose sum is σ = 131255964. Its totient is φ = 33334816.

The previous prime is 66669619. The next prime is 66669683. The reversal of 66669664 is 46696666.

It is a happy number.

66669664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1041682 + ... + 1041745.

It is an arithmetic number, because the mean of its divisors is an integer number (10937997).

Almost surely, 2^66669664 is an apocalyptic number.

It is an amenable number.

66669664 is a deficient number, since it is larger than the sum of its proper divisors (64586300).

66669664 is a wasteful number, since it uses less digits than its factorization.

66669664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2083437 (or 2083429 counting only the distinct ones).

The product of its digits is 1679616, while the sum is 49.

The square root of 66669664 is about 8165.1493556456. The cubic root of 66669664 is about 405.4862097428.

The spelling of 66669664 in words is "sixty-six million, six hundred sixty-nine thousand, six hundred sixty-four".