668504893 has 6 divisors (see below), whose sum is σ = 777648606. Its totient is φ = 573004152.

The previous prime is 668504849. The next prime is 668504909. The reversal of 668504893 is 398405866.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 658538244 + 9966649 = 25662^2 + 3157^2 .

It is not a de Polignac number, because 668504893 - 2²⁵ = 634950461 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49), and also a Moran number because the ratio is a prime number: 13642957 = 668504893 / (6 + 6 + 8 + 5 + 0 + 4 + 8 + 9 + 3).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668504833) 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 5 ways as a sum of consecutive naturals, for example, 6821430 + ... + 6821527.

It is an arithmetic number, because the mean of its divisors is an integer number (129608101).

Almost surely, 2^668504893 is an apocalyptic number.

It is an amenable number.

668504893 is a deficient number, since it is larger than the sum of its proper divisors (109143713).

668504893 is a wasteful number, since it uses less digits than its factorization.

668504893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13642971 (or 13642964 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 49.

The square root of 668504893 is about 25855.4615700436. The cubic root of 668504893 is about 874.3826471983.

The spelling of 668504893 in words is "six hundred sixty-eight million, five hundred four thousand, eight hundred ninety-three".