66668899 has 4 divisors (see below), whose sum is σ = 72729720. Its totient is φ = 60608080.

The previous prime is 66668897. The next prime is 66668923. The reversal of 66668899 is 99886666.

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 66668899 - 2¹ = 66668897 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66668897) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3030394 + ... + 3030415.

It is an arithmetic number, because the mean of its divisors is an integer number (18182430).

Almost surely, 2^66668899 is an apocalyptic number.

66668899 is a deficient number, since it is larger than the sum of its proper divisors (6060821).

66668899 is a wasteful number, since it uses less digits than its factorization.

66668899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6060820.

The product of its digits is 6718464, while the sum is 58.

The square root of 66668899 is about 8165.1025100730. The cubic root of 66668899 is about 405.4846588218.

The spelling of 66668899 in words is "sixty-six million, six hundred sixty-eight thousand, eight hundred ninety-nine".