668928428 has 24 divisors (see below), whose sum is σ = 1338573600. Its totient is φ = 286530048.

The previous prime is 668928401. The next prime is 668928433. The reversal of 668928428 is 824829866.

It is a self number, because there is not a number n which added to its sum of digits gives 668928428.

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 7 ways as a sum of consecutive naturals, for example, 58268 + ... + 68796.

It is an arithmetic number, because the mean of its divisors is an integer number (55773900).

Almost surely, 2^668928428 is an apocalyptic number.

It is an amenable number.

668928428 is an abundant number, since it is smaller than the sum of its proper divisors (669645172).

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

668928428 is a wasteful number, since it uses less digits than its factorization.

668928428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12809 (or 12807 counting only the distinct ones).

The product of its digits is 2654208, while the sum is 53.

The square root of 668928428 is about 25863.6507090550. The cubic root of 668928428 is about 874.5672648814.

The spelling of 668928428 in words is "six hundred sixty-eight million, nine hundred twenty-eight thousand, four hundred twenty-eight".