668768823 has 6 divisors (see below), whose sum is σ = 965999424. Its totient is φ = 445845876.

The previous prime is 668768819. The next prime is 668768827. The reversal of 668768823 is 328867866.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (668768819) and next prime (668768827).

It is not a de Polignac number, because 668768823 - 2² = 668768819 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 668768823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668768827) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37153815 + ... + 37153832.

It is an arithmetic number, because the mean of its divisors is an integer number (160999904).

Almost surely, 2^668768823 is an apocalyptic number.

668768823 is a deficient number, since it is larger than the sum of its proper divisors (297230601).

668768823 is a wasteful number, since it uses less digits than its factorization.

668768823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74307653 (or 74307650 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 54.

The square root of 668768823 is about 25860.5650170293. The cubic root of 668768823 is about 874.4977026753.

The spelling of 668768823 in words is "six hundred sixty-eight million, seven hundred sixty-eight thousand, eight hundred twenty-three".