668320802021 has 8 divisors (see below), whose sum is σ = 668892400800. Its totient is φ = 667749361680.

The previous prime is 668320802011. The next prime is 668320802063. The reversal of 668320802021 is 120208023866.

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 668320802021 - 2¹⁰ = 668320800997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668320802011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9332570 + ... + 9403908.

It is an arithmetic number, because the mean of its divisors is an integer number (83611550100).

Almost surely, 2^668320802021 is an apocalyptic number.

It is an amenable number.

668320802021 is a deficient number, since it is larger than the sum of its proper divisors (571598779).

668320802021 is a wasteful number, since it uses less digits than its factorization.

668320802021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79219.

The product of its (nonzero) digits is 55296, while the sum is 38.

Adding to 668320802021 its reverse (120208023866), we get a palindrome (788528825887).

The spelling of 668320802021 in words is "six hundred sixty-eight billion, three hundred twenty million, eight hundred two thousand, twenty-one".