668844378 has 56 divisors (see below), whose sum is σ = 1522610208. Its totient is φ = 220222152.

The previous prime is 668844359. The next prime is 668844389. The reversal of 668844378 is 873448866.

It is a Harshad number since it is a multiple of its sum of digits (54).

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 27 ways as a sum of consecutive naturals, for example, 118251 + ... + 123777.

It is an arithmetic number, because the mean of its divisors is an integer number (27189468).

Almost surely, 2^668844378 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668844378, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (761305104).

668844378 is an abundant number, since it is smaller than the sum of its proper divisors (853765830).

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

668844378 is an equidigital number, since it uses as much as digits as its factorization.

668844378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5630 (or 5615 counting only the distinct ones).

The product of its digits is 6193152, while the sum is 54.

The square root of 668844378 is about 25862.0257907226. The cubic root of 668844378 is about 874.5306339283.

The spelling of 668844378 in words is "six hundred sixty-eight million, eight hundred forty-four thousand, three hundred seventy-eight".