668285778 has 8 divisors (see below), whose sum is σ = 1336571568. Its totient is φ = 222761924.

The previous prime is 668285767. The next prime is 668285797. The reversal of 668285778 is 877582866.

It is a happy number.

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

668285778 is an admirable number.

It is a Curzon 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, 55690476 + ... + 55690487.

It is an arithmetic number, because the mean of its divisors is an integer number (167071446).

Almost surely, 2^668285778 is an apocalyptic number.

668285778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668285778 is a wasteful number, since it uses less digits than its factorization.

668285778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111380968.

The product of its digits is 9031680, while the sum is 57.

The square root of 668285778 is about 25851.2239168671. The cubic root of 668285778 is about 874.2871049956.

The spelling of 668285778 in words is "six hundred sixty-eight million, two hundred eighty-five thousand, seven hundred seventy-eight".