668989888 has 28 divisors (see below), whose sum is σ = 1517174512. Its totient is φ = 286709760.

The previous prime is 668989879. The next prime is 668989897. The reversal of 668989888 is 888989866.

It is an interprime number because it is at equal distance from previous prime (668989879) and next prime (668989897).

It is a tau number, because it is divible by the number of its divisors (28).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 746193 + ... + 747088.

It is an arithmetic number, because the mean of its divisors is an integer number (54184804).

Almost surely, 2^668989888 is an apocalyptic number.

It is an amenable number.

668989888 is an abundant number, since it is smaller than the sum of its proper divisors (848184624).

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

668989888 is a wasteful number, since it uses less digits than its factorization.

668989888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1493300 (or 1493290 counting only the distinct ones).

The product of its digits is 95551488, while the sum is 70.

The square root of 668989888 is about 25864.8388357631. The cubic root of 668989888 is about 874.5940486426.

The spelling of 668989888 in words is "six hundred sixty-eight million, nine hundred eighty-nine thousand, eight hundred eighty-eight".