28304021668 has 24 divisors (see below), whose sum is σ = 53368253568. Its totient is φ = 13057012896.

The previous prime is 28304021657. The next prime is 28304021671. The reversal of 28304021668 is 86612040382.

It is a super-2 number, since 2×28304021668² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28304021668.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24646 + ... + 239197.

It is an arithmetic number, because the mean of its divisors is an integer number (2223677232).

Almost surely, 2^28304021668 is an apocalyptic number.

It is an amenable number.

28304021668 is a deficient number, since it is larger than the sum of its proper divisors (25064231900).

28304021668 is a wasteful number, since it uses less digits than its factorization.

28304021668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265923 (or 265921 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 40.

The spelling of 28304021668 in words is "twenty-eight billion, three hundred four million, twenty-one thousand, six hundred sixty-eight".