668520878 has 8 divisors (see below), whose sum is σ = 1003317840. Its totient is φ = 334081600.

The previous prime is 668520863. The next prime is 668520883. The reversal of 668520878 is 878025866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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, 84698 + ... + 92253.

It is an arithmetic number, because the mean of its divisors is an integer number (125414730).

Almost surely, 2^668520878 is an apocalyptic number.

668520878 is a deficient number, since it is larger than the sum of its proper divisors (334796962).

668520878 is a wasteful number, since it uses less digits than its factorization.

668520878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178842.

The product of its (nonzero) digits is 1290240, while the sum is 50.

The square root of 668520878 is about 25855.7706905054. The cubic root of 668520878 is about 874.3896164293.

The spelling of 668520878 in words is "six hundred sixty-eight million, five hundred twenty thousand, eight hundred seventy-eight".