668931984 has 120 divisors (see below), whose sum is σ = 2148344640. Its totient is φ = 190335744.

The previous prime is 668931971. The next prime is 668932003. The reversal of 668931984 is 489139866.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 668931984.

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 23 ways as a sum of consecutive naturals, for example, 269919 + ... + 272385.

It is an arithmetic number, because the mean of its divisors is an integer number (17902872).

Almost surely, 2^668931984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668931984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1074172320).

668931984 is an abundant number, since it is smaller than the sum of its proper divisors (1479412656).

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

668931984 is a wasteful number, since it uses less digits than its factorization.

668931984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2757 (or 2748 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 54.

The square root of 668931984 is about 25863.7194540924. The cubic root of 668931984 is about 874.5688146016.

The spelling of 668931984 in words is "six hundred sixty-eight million, nine hundred thirty-one thousand, nine hundred eighty-four".