668039918801 has 4 divisors (see below), whose sum is σ = 691075778100. Its totient is φ = 645004059504.

The previous prime is 668039918797. The next prime is 668039918869. The reversal of 668039918801 is 108819930866.

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

It can be written as a sum of positive squares in 2 ways, for example, as 275100250000 + 392939668801 = 524500^2 + 626849^2 .

It is a cyclic number.

It is not a de Polignac number, because 668039918801 - 2² = 668039918797 is a prime.

It is a super-2 number, since 2×668039918801² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668039918501) 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, 11517929606 + ... + 11517929663.

It is an arithmetic number, because the mean of its divisors is an integer number (172768944525).

Almost surely, 2^668039918801 is an apocalyptic number.

It is an amenable number.

668039918801 is a deficient number, since it is larger than the sum of its proper divisors (23035859299).

668039918801 is a wasteful number, since it uses less digits than its factorization.

668039918801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23035859298.

The product of its (nonzero) digits is 4478976, while the sum is 59.

The spelling of 668039918801 in words is "six hundred sixty-eight billion, thirty-nine million, nine hundred eighteen thousand, eight hundred one".