668815028 has 12 divisors (see below), whose sum is σ = 1337630112. Its totient is φ = 286635000.

The previous prime is 668815019. The next prime is 668815039. The reversal of 668815028 is 820518866.

668815028 is an admirable number.

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 668815028.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11943098 + ... + 11943153.

It is an arithmetic number, because the mean of its divisors is an integer number (111469176).

Almost surely, 2^668815028 is an apocalyptic number.

It is an amenable number.

668815028 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.

668815028 is a wasteful number, since it uses less digits than its factorization.

668815028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23886262 (or 23886260 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 44.

The square root of 668815028 is about 25861.4583502168. The cubic root of 668815028 is about 874.5178417899.

The spelling of 668815028 in words is "six hundred sixty-eight million, eight hundred fifteen thousand, twenty-eight".