668945392127 has 4 divisors (see below), whose sum is σ = 690524275776. Its totient is φ = 647366508480.

The previous prime is 668945392117. The next prime is 668945392147. The reversal of 668945392127 is 721293549866.

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 668945392127 - 2²⁸ = 668676956671 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 668945392127.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668945392117) 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 3 ways as a sum of consecutive naturals, for example, 10789441778 + ... + 10789441839.

It is an arithmetic number, because the mean of its divisors is an integer number (172631068944).

Almost surely, 2^668945392127 is an apocalyptic number.

668945392127 is a deficient number, since it is larger than the sum of its proper divisors (21578883649).

668945392127 is a wasteful number, since it uses less digits than its factorization.

668945392127 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21578883648.

The product of its digits is 39191040, while the sum is 62.

The spelling of 668945392127 in words is "six hundred sixty-eight billion, nine hundred forty-five million, three hundred ninety-two thousand, one hundred twenty-seven".